JP2003042274A - Automatic transmission - Google Patents

Abstract

(57) [Summary] An object of the present invention is to form a shelf pressure of hydraulic oil for alleviating a shock generated when a hydraulically actuated friction engagement element is fastened by a shelf pressure control valve having a simple structure. It is in. For this reason, the present invention provides a shelf pressure control valve in an oil passage for supplying and discharging hydraulic oil to a hydraulically actuated friction engagement element of an automatic transmission. The pressure is quickly increased by moving the spool valve to a position where the supply port and the output port are communicated by the urging force of the urging means, and in the middle period of supply of the hydraulic oil, the supply port and the output are output by the feedback pressure of the feedback circuit. The spool valve is moved to a position where the port is shut off, and a shelf pressure is formed by the orifice of the bypass passage. The spool valve body is moved to the position where
When the hydraulic oil is discharged, the supply port and the output port are connected by a one-way valve of the bypass circuit, so that the pressure is rapidly reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission, and more particularly, to an accumulator or an electric control of a shelf pressure of hydraulic oil for alleviating a shock generated when a hydraulically operated friction engagement element is engaged. The present invention relates to an automatic transmission that can be formed by a shelf pressure control valve having a simple structure without requiring a pressure regulating valve.

[0002]

2. Description of the Related Art Vehicles such as automobiles are equipped with a transmission in order to appropriately take out the driving force generated by an internal combustion engine in accordance with the operating state. The transmission includes a manual transmission that shifts manually and an automatic transmission that shifts automatically.

Some automatic transmissions are provided with hydraulically actuated friction engagement elements such as clutches and brakes in order to change the power transmission path to change gears. The hydraulically actuated friction engagement element is fastened by supplying hydraulic oil and released by discharging hydraulic oil.

A clutch, which is a hydraulically actuated friction engagement element, causes a shock when there is a difference in rotational speed between two members, a driving side and a driven side, when engaging by supplying hydraulic oil. There is. Therefore, in the automatic transmission, the rise in the pressure of the hydraulic oil supplied to the clutch is temporarily moderated to form a shelf pressure, and the shock at the time of engagement is relieved. This shelf pressure is formed by an accumulator provided in a hydraulic circuit, an electrically controlled pressure regulating valve, or the like.

[0005]

By the way, in order to form the shelf pressure by the accumulator and obtain a sufficient shock absorbing effect, it is necessary to increase the volume of the accumulator. Accumulators with such a large volume
Since it is difficult to fit it in the valve body of the automatic transmission, it is to be accommodated in the transmission case.

However, when the accumulator is housed in the transmission case, the hydraulic circuit in the transmission case is complicated to handle, and the shape and rigidity of the transmission case are affected.

Further, when the shelf pressure is formed by the accumulator, it is necessary to provide an orifice in the hydraulic circuit upstream of the accumulator, but since this orifice acts to delay the clutch engagement time, it is possible to quickly There is a problem that affects gear shifting.

Further, since the accumulator forms the shelf pressure by accumulating the working oil, the apparent working oil consumption increases while the shelf pressure is being formed, and the oil amount balance of the hydraulic circuit system increases. There is an inconvenience that is disadvantageous in the above.

On the other hand, when the pressure regulating valve is electrically controlled to form the shelf pressure, it is necessary to provide an electronic control valve, and further various sensors such as a temperature sensor and a rotation speed sensor are required. Since it is necessary to prepare a control algorithm that assumes all situations of the transmission, there is a disadvantage in terms of cost.

[0010]

In order to eliminate such inconveniences, the present invention relates to an automatic transmission for switching gears by engaging or disengaging hydraulically actuated friction engagement elements to switch gears for transmission. A shelf pressure control valve is provided in an oil passage for supplying and discharging hydraulic oil to the hydraulically operated friction engagement element, and this shelf pressure control valve is provided with a spool valve body slidably installed inside a sliding hole of a valve body, A position where the valve body is provided with a supply port and an output port communicating with the sliding hole, the spool valve element is provided with a small diameter portion and a land portion, and the supply port and the output port are communicated with each other by the small diameter portion. Is provided with an urging means for applying an urging force to the spool valve body so as to move the spool valve body, and moves the spool valve body to a position where communication between the supply port and the output port is blocked by a land portion. So that a feedback circuit for applying a feedback pressure extracted from the hydraulic oil on the output port side to the spool valve body is provided, and an orifice is provided in a bypass circuit that bypasses the supply port and the output port and connects the oil passage. In addition, a one-way valve that allows the flow of hydraulic oil only from the output port side to the supply port side is provided. The spool valve element is moved to a position where the supply port and the output port are communicated with each other by the small diameter portion to rapidly increase the pressure. The spool valve element is moved to a position where communication with the port is blocked by the land portion, and To gradually increase the pressure to form a shelf pressure, and the supply port and the output port are communicated by the small diameter portion by the feedback pressure of the feedback circuit until the set value is reached in the latter stage of the supply of the hydraulic oil. The spool valve element is moved to the position to quickly increase the pressure, and when the hydraulic oil is discharged from the hydraulically actuated friction engagement element in the previous period, the one-way valve in the bypass circuit bypasses the supply port and the output port. The oil passages are communicated with each other to rapidly reduce the pressure.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The automatic transmission according to the present invention supplies hydraulic oil to a hydraulically-actuated frictional engagement element by means of a shelf pressure control valve provided in an oil passage for supplying and discharging hydraulically-operated frictional engagement element. In the first half of the supply during the operation, the spool valve element is moved to the position where the supply port and the output port are communicated by the small diameter portion by the urging force of the urging means to quickly increase the pressure, By the feedback pressure of the feedback circuit, the spool valve element is moved to the position where the communication between the supply port and the output port is blocked by the land, and the orifice of the bypass passage moderates the rise in pressure to form a shelf pressure, which operates. In the latter half of oil supply, the spool valve element is moved to the position where the feed port and output port communicate with each other by the small diameter section until the set value is reached. To raise the pressure quickly, and when the hydraulic oil is discharged from the hydraulically actuated friction engagement element, the one-way valve in the bypass circuit bypasses the supply port and the output port to connect the oil passage to establish the pressure. By rapidly lowering the rack pressure, the rack pressure is formed by the mechanical structure of the valve body of the rack pressure control valve, the spool valve element, the biasing means, the feedback circuit, the orifice of the bypass passage, and the one-way valve. You can

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 show a first embodiment of the present invention. In FIG. 7, 2 is an internal combustion engine mounted on a vehicle (not shown), 4 is a crankshaft, 6 is an automatic transmission including a continuously variable transmission, and 8 is a transmission case. Automatic transmission 6
Is a drive-side shaft 10 that is provided coaxially with the crankshaft 4 of the engine 2 and that is supported by the transmission case 8. The driven-side shaft 10 is provided in parallel with the drive-side shaft 10. A transmission case 12 is pivotally supported on the transmission case 8.

In the automatic transmission 6, a drive side shaft 10 is provided with a drive side pulley 14, and a driven side shaft 12 is provided with a driven side pulley 16.
And a belt 18 is wound around the drive side pulley 14 and the driven side pulley 16.

The drive side pulley 14 includes a drive side fixed pulley portion piece 20 fixed to the drive side shaft 10 and a drive side movable pulley portion piece 22 mounted on the drive side shaft 10 so as to be axially movable and non-rotatable. Consists of. On the back surface of the drive-side movable pulley section 22, the drive-side hydraulic chamber 26 is provided by the drive-side housing 24.
Is formed.

The driven pulley 16 includes a driven fixed pulley portion 28 fixed to the driven shaft 12 and a driven movable pulley portion 30 mounted on the driven shaft 12 so as to be axially movable but non-rotatable. Consists of. On the back surface of the driven-side movable pulley portion 30, the driven-side hydraulic chamber 34 is provided by the driven-side housing 32.
An adjusting spring 36 that presses the driven-side movable pulley portion 30 toward the driven-side fixed pulley portion 28 is provided in the driven-side hydraulic chamber 34.

Drive side pulley 14 and driven side pulley 16
Changes the groove width relatively by the pressure oil of the primary pressure and the line pressure supplied to the driving hydraulic chamber 26 and the driven hydraulic chamber 34, and relatively increases and decreases the radius of gyration of the belt 18 to shift gears. The ratio is continuously changed.

The automatic transmission 6 includes a crankshaft 4 and a drive-side shaft 10 on the input side of the drive-side shaft 10 in the vicinity of the engine 2.
An input shaft 38 is provided coaxially with the input shaft 38. The input shaft 38 is provided with a torque converter 40 between the input side and the output side of the crankshaft 4, and a forward / reverse switching mechanism 42 is provided between the output side and the input side of the drive-side shaft 10. An oil pump 44 is provided between the mechanisms 42.

The forward / reverse switching mechanism 42 includes a forward clutch 46 and a reverse brake 4 which are hydraulically operated friction engagement elements.
8 and. The forward clutch 46 and the reverse brake 48 are respectively engaged or released by the supply and discharge of hydraulic oil, and switch the power transmission path between the input shaft 38 and the drive side shaft 10 to rotate the input shaft 38 normally. It is rotated or reversed and transmitted to the drive shaft 10. The oil pump 44
Supplies the generated pressure oil as operating oil to the drive-side hydraulic chamber 26, the driven-side hydraulic chamber 34, the forward clutch 46, the reverse brake 48, and the output clutch 52 described later.

The automatic transmission 6 is provided with an output shaft 50 coaxially arranged with the driven shaft 12 on the output side of the driven shaft 12. The output shaft 50 is the driven shaft 12
An output clutch 52 is provided between the output side and the input side. Further, the continuously variable transmission 6 is provided by rotatably supporting a counter shaft 54 arranged in parallel with the output shaft 50. A reduction gear train 56 is provided between the output shaft 50 and the counter shaft 54.

Further, the automatic transmission 6 is provided with a differential 58, which is arranged parallel to the counter shaft 54, axially supported on the transmission case 8. A final gear train 62 is provided between the counter shaft 54 and the differential case 60 of the differential 58. Differential 58
One end side of the drive shafts 64, 64 is connected to each of the drive shafts, and drive wheels (not shown) are attached to the other end sides of the drive shafts 64, 64.

The drive side pulley 14, the driven side pulley 16, the torque converter 40, the forward / reverse switching mechanism 42 and the output clutch 52 are controlled by a shift control device 66 as shown in FIG. The gear change control device 66 includes the oil pump 4
A hydraulic circuit 68 for extracting control hydraulic oil from the discharge pressure generated by No. 4 is provided.

The hydraulic circuit 68 of the shift control device 66 has a line pressure adjusting valve 7 for adjusting the discharge pressure of the oil pump 44 to a line pressure in a line pressure oil passage 70 communicating with the oil pump 44.
2 is provided, a clutch pressure regulating valve 76 for extracting the hydraulic oil of the clutch pressure from the line pressure of the line pressure oil passage 70 to the clutch pressure oil passage 74 is provided, and the clutch pressure oil passage 74 is provided with a manual valve 78.
Contact us to establish. The operation of the line pressure regulating valve 72 and the clutch pressure regulating valve 76 is controlled by the shift control means 80. The manual valve 78 is switched by a select lever (not shown).

The manual valve 78 is provided by connecting one end sides of the forward clutch oil passage 82 and the reverse brake oil passage 84. The forward movement clutch oil passage 82 and the reverse movement brake oil passage 84 are provided at the other ends thereof in communication with the forward movement clutch 46 and the reverse movement brake 48 of the forward-reverse switching mechanism 42, respectively. The manual valve 78 supplies and discharges the hydraulic oil of the clutch pressure to the forward clutch 46 and the reverse brake 48 through the forward clutch oil passage 82 and the reverse brake oil passage 84, respectively. The engagement state and the backward engagement state are switched.

The gear shift control device 66 uses the line pressure in the line pressure oil passage 70 as a secondary pressure to drive the driven pulley 16.
To the driven side hydraulic chamber 34 of the drive side pulley 14 and the ratio pressure extracted from the line pressure of the line pressure oil passage 70 by a ratio pressure regulating valve (not shown).
6 to change the gear ratio of the automatic transmission 6. Further, the shift control device 66 supplies the output clutch pressure extracted from the line pressure of the line pressure oil passage 70 by the output clutch pressure regulating valve (not shown) to the output clutch 52 to engage the output clutch 52.・ Release it. The operation of the ratio pressure regulating valve and the output clutch pressure regulating valve is controlled by the shift control means 80.

In the middle of the forward clutch oil passage 82,
A shelf pressure control valve 86 that forms a shelf pressure in the hydraulic oil of the clutch pressure supplied to the forward clutch 46 is provided.
A shelf pressure control valve 88 that forms a shelf pressure in the hydraulic oil of the clutch pressure supplied to the reverse brake 48 is provided in the middle of the reverse brake oil passage 84. The shelf pressure control valve 86 of the forward clutch pressure oil passage 82 and the shelf pressure control valve 88 of the reverse brake oil passage 84 are configured in the same manner, and therefore one shelf pressure control valve 86 will be cited below. And explain.

As shown in FIG. 1, the shelf pressure control valve 86 interposed in the forward clutch oil passage 82 connects the forward clutch oil passage 82 to the supply-side forward clutch oil passage 82A and the output-side forward clutch. It is divided into an oil passage 82B. The shelf pressure control valve 86 includes a spool valve body 94 in a sliding hole 92 of a valve body 90.
Is installed so that it can slide.

In the valve body 90, a supply port 96 which communicates with a manual valve 78 on the hydraulic oil supply side through a supply-side forward clutch oil passage 82A and opens into a slide hole 92, and the sliding of the supply port 96. The first and second output ports 98 and 100 are opened in the sliding holes 92 on both sides in the hole axis direction and communicate with the forward clutch 46 on the hydraulically operated friction engagement element side by the output-side forward clutch oil passage 82B. Is provided.

The supply port 96 is formed in a groove shape in the circumferential direction at the axially central portion of the sliding hole 92. First
The output port 98 is formed in a groove shape in the circumferential direction on one side of the supply port 96 in the axial direction. Second output port 1
00 is formed in a groove shape in the circumferential direction on the other side in the axial direction of the supply port 96.

The spool valve element 94 is provided with a small diameter portion 102 at a central portion in the axial direction, and first and second land portions 104 and 106 are provided on both sides in the axial direction of the small diameter portion 102, respectively. The small-diameter portion 102 has the first and second output ports 9
8 and 100 has a length L2 in the axial direction of the spool valve element shorter than the length L1 in the axial direction of the sliding hole between the adjacent portions (L1>
L2) and the first and second land portions 104 and 106 are provided with an overlap margin L3.

The small-diameter portion 102 includes the supply port 96 and the first
It selectively communicates with either one of the second output ports 98 and 100. The first land portion 104 is provided on one side of the small diameter portion 102 in the spool valve body axial direction, and cuts off the communication between the supply port 96 and the first output port 98 when the supply port 96 and the second output port 100 are connected. To do. The second land portion 106 is provided on the other side of the small diameter portion 102 in the axial direction of the spool valve body, and blocks the communication between the supply port 96 and the second output port 100 when the supply port 96 and the first output port 98 communicate with each other. To do.

The valve body 90 is provided by partitioning and forming a first chamber 108 between the first land portion 104 of the spool valve body 94 and one side of the sliding hole 92 in the axial direction. The second chamber 110 is partitioned and formed between the second land portion 106 and the other side of the sliding hole 92 in the axial direction.

In the second chamber 110 on the other side in the axial direction of the sliding hole,
The supply port 96 and the first output port 98 have the small diameter portion 102.
A spring 112 is provided as a biasing unit that applies a biasing force to the second land portion 106 of the spool valve body 94 so as to move the spool valve body 94 to a position in which the spool valve body 94 communicates with each other.

In the first chamber 108 located on one side in the axial direction of the sliding hole,
One end side of the feedback circuit 114, which communicates with the output side forward clutch oil passage 82B, communicates with the other end side. The feedback circuit 114 includes an orifice 116.
Is provided. In the feedback circuit 114, the supply port 96 and the first and second output ports 98 and 100 are first and second.
To move the spool valve element 94 to a position where the communication is blocked by the second land portions 104 and 106, the first and second
The feedback pressure extracted from the hydraulic oil in the output-side forward clutch oil passage 82B on the output port 98/100 side is set to the first value.
A feedback pressure is applied to the first land portion 104 of the spool valve element 94 from one side in the sliding hole axial direction in the direction opposite to the urging force of the spring 112.

The shelf pressure control valve 86 bypasses the supply port 96 and the first and second output ports 98 and 100,
A first bypass circuit 118 that connects the supply-side forward clutch oil passage 82A and the output-side forward clutch oil passage 82B is provided. An orifice 120 is provided in the first bypass circuit 118.

Further, the shelf pressure control valve 86 bypasses the supply port 96 and the first and second output ports 98 and 100 via the first bypass circuit 118 to form the supply side forward clutch oil passage 82A. A second bypass circuit 122 that communicates with the output-side forward clutch oil passage 82B is provided. A one-way valve 124 is provided in the second bypass circuit 122. The one-way valve 124 has the first and second output ports 98,
The hydraulic oil is allowed to flow only from the 100 side to the supply port 96 side.

Next, the operation will be described.

The automatic transmission 6 relatively increases or decreases the radius of rotation of the belt 18 wound around the driving pulley 14 and the driven pulley 16 by the driving force of the internal combustion engine 2,
The gear ratio is continuously changed, and the forward clutch 46, which is a hydraulically operated friction engagement element of the forward / reverse switching mechanism 42, is used.
The power transmission path is switched between the forward drive and the reverse drive by engaging or releasing the reverse brake 48 and the reverse brake 48 with hydraulic oil.

The forward clutch 46 and the reverse brake 48, which are the hydraulically actuated friction engagement elements, have a shelf pressure control valve 86 for temporarily gradually increasing the pressure of the supplied hydraulic oil.
・ 88 is provided. The shelf pressure control valves 86 and 88 operate as follows.

The shelf pressure control valve 86 for temporarily gradually increasing the pressure of the hydraulic oil supplied to the forward clutch 46,
When the pressure of the hydraulic oil in the output-side forward clutch oil passage 82B is zero, as shown in FIG. 3, the supply port 96 and the first output port 98 are connected in the axial direction of the sliding hole through which the small diameter portion 102 communicates. The spool valve element 94 is moved to the side position by the urging force of the spring 112.

The shelf pressure control valve 86 starts the supply of the hydraulic oil in the supply-side forward clutch oil passage 82A from time t1 in FIG. 2 when the pressure of the hydraulic oil in the output-side forward clutch oil passage 82B is zero. Then, the working oil flows from the supply port 96 to the first output port 98 via the small diameter portion 102, and the working oil flows via the orifice 120 of the first bypass circuit 118, so that the pressure of the output side forward clutch oil passage 82B. Rises.

The shelf pressure control valve 86 controls the rising pressure of the output side forward clutch oil passage 82B by the feedback circuit 114.
As a result, it acts as feedback pressure on the first chamber 108, and the spool valve element 94 is gradually moved toward the other side in the sliding hole axial direction.

The spool valve element 94, which is moved toward the other side in the axial direction of the sliding hole, has the output side forward clutch oil passage 82B.
When the hydraulic oil of No. 2 further rises, as shown in FIG. 4, the communication between the supply port 96 and the first output port 98 is cut off by the first land portion 104 (time t2 in FIG. 2). At this time,
The supply port 96 and the second output port 100 are disconnected from each other by the second land portion 106 by the overlap margin L3 of the first and second land portions 104 and 106.

As a result, the shelf pressure control valve 86 has the first and second output ports 98.10 from the start of supply at time t1 in FIG.
In the first half A of hydraulic fluid supply until time t2 when 0 is closed,
The urging force of the spring 112 causes the supply port 96 and the first
The spool valve element 94 is moved to a position where the small diameter portion 102 communicates with the output port 98, and the pressure is rapidly increased.

As shown in FIG. 4, in the shelf pressure control valve 86, when the communication between the supply port 96 and the first and second output ports 98 and 100 is cut off by the first and second land portions 104 and 106, Depending on the pressure difference between the supply-side forward clutch oil passage 82A and the output-side forward clutch oil passage 82B, hydraulic oil flows only through the orifice 120 of the first bypass circuit 118, and the output-side forward clutch oil passage 82B. The pressure is gradually increased.

In the shelf pressure control valve 86, the gradually increasing pressure of the output side forward clutch oil passage 82B is acted as feedback pressure on the first chamber 108 by the feedback circuit 114, and the spool valve element 94 moves in the axial direction of the sliding hole. It is gradually moved toward the other side.

When the hydraulic oil in the output side forward clutch oil passage 82B further rises, the spool valve element 94, which is gradually moved toward the other side in the sliding hole axial direction, is connected to the supply port 96 as shown in FIG. The small diameter portion 102 communicates with the second output port 100 (time t3 in FIG. 2). At this time, the supply port 96 and the first output port 98 are
Communication is blocked by the first land portion 104 by the overlap margin L3 of the second land portions 104 and 106.

As a result, the shelf pressure control valve 86 is closed from the closing of the first and second output ports 98 and 100 at time t2 in FIG. 2 to the time t3 when the supply port 96 and the second output port 100 are communicated with each other. During the middle period B of the hydraulic oil supply, the feed port 96 is fed by the feedback pressure of the feedback circuit 114.
The spool valve element 94 is moved to a position where the first and second output ports 98 and 100 are cut off from the communication by the first and second land portions 104 and 106, and pressure is applied by the orifice 120 of the first bypass passage 118. The rise is moderated to form a shelf pressure.

As shown in FIG. 5, the shelf pressure control valve 86 allows the supply port 96 and the second output port 100 to communicate with each other.
The pressure in the output-side forward clutch oil passage 82B rises, the working oil flows from the supply port 96 to the second output port 100 via the small diameter portion 102, and at the same time, the first bypass circuit 118.
The hydraulic oil flows through the orifice 120, and the pressure in the output-side forward clutch oil passage 82B rises.

The shelf pressure control valve 86 controls the rising pressure of the output side forward clutch oil passage 82B by the feedback circuit 114.
As a result, it acts as a feedback pressure on the first chamber 108, and the spool valve body 94 is moved toward the other side in the sliding hole axial direction.

The spool valve element 94, which is moved toward the other side in the axial direction of the sliding hole, has the output side forward clutch oil passage 82B.
When the hydraulic oil in No. 2 further rises, the communication ratio between the supply port 96 and the second output port 100 increases.

As a result, the shelf pressure control valve 86 causes the feedback circuit to operate in the latter half C of the hydraulic oil supply until the time t4 when the supply pressure reaches the set pressure from the communication between the supply port 96 and the second output port 100 at the time t3 in FIG. The feedback pressure of 114 moves the spool valve element 94 to a position where the supply port 96 and the second output port 100 are communicated with each other by the small diameter portion 102, and the pressure is rapidly increased. At time t4, the supply pressure of the input side forward clutch oil passage 82A and the output pressure of the output side forward clutch oil passage 82B match.

On the other hand, when the hydraulic oil is discharged from the forward clutch 46, the shelf pressure control valve 86, as shown in FIG. 6, even if the supply port 96 and the first and second output ports 98 and 100 are provided.
Even if and are disconnected from each other by the first and second lands 104 and 106, the supply-side forward clutch oil is supplied via the orifice 120 of the first bypass circuit 118 and the one-way valve 124 of the second bypass circuit 122. Hydraulic fluid flows to the passage 82A.

As a result, the shelf pressure control valve 86 uses the one-way valve 124 of the second bypass circuit 122 and the supply port 96 and the first port when the hydraulic oil is discharged from the forward clutch 46.
-By bypassing the second output ports 98 and 100, the input side forward movement clutch oil passage 82A and the output side forward movement clutch oil passage 82B are made to communicate with each other so that the pressure can be quickly reduced and a shelf pressure is formed. Never be done.

As described above, the automatic transmission 6 supplies the hydraulic oil to the forward clutch 46 by the shelf pressure control valve 86 provided in the forward clutch oil passage 82 for supplying and discharging the hydraulic oil to the forward clutch 46. In the first half of the supply of hydraulic oil, the pressure is quickly increased, in the middle of the hydraulic oil supply, the pressure is gradually increased to form a shelf pressure, and in the latter half of the hydraulic oil supply, the pressure is rapidly increased. The pressure is rapidly reduced when the hydraulic oil is discharged from the forward clutch 46.

As a result, in the automatic transmission 6, the valve body 90 of the shelf pressure control valve 86, the spool valve body 94, the feedback circuit 114, the first and second bypass passages 118.
The mechanical configuration of the orifices 22 and the one-way valve 124 of 22 makes it possible to easily form the shelf pressure.

Therefore, the automatic transmission 6 does not have an accumulator or an electrically controlled pressure regulating valve as in the conventional case, but has a shelf pressure for alleviating a shock generated when the forward clutch 46 is engaged. Can be formed by the shelf pressure control valve 86 having a simple structure. Further, in the automatic transmission 6, similarly, the shelf pressure for reducing the shock generated when the reverse brake 48 is engaged can be formed by the shelf pressure control valve 88 having a simple structure.

For this reason, the automatic transmission 6 does not have the problem of adversely affecting the handling of the hydraulic circuit and the shape of the transmission case, unlike the accumulator, and the apparent hydraulic oil consumption increases due to the increase in the hydraulic oil consumption. It is possible to avoid disadvantages that are disadvantageous in terms of the oil balance of the system, and it is possible to eliminate the adverse effect on rapid gear shifting due to the orifice provided in the hydraulic circuit upstream of the accumulator.
Since it is not necessary to prepare various sensors and control algorithms like an electrically controlled pressure regulating valve, it can be implemented cost effectively.

9 to 13 show the second embodiment. In the second embodiment, the portions having the same functions as those in the first embodiment will be described with the same reference numerals. In the automatic transmission 6 of the second embodiment, as shown in FIGS. 7 and 8, the hydraulic circuit 68 of the speed change control device 66 uses hydraulic oil of the clutch pressure supplied to the forward clutch 46 of the forward / reverse switching mechanism 42. A shelf pressure control valve 86 that forms a shelf pressure is provided and a shelf pressure control valve 88 that forms a shelf pressure in the hydraulic oil of the clutch pressure supplied to the reverse brake 48 is provided.

As shown in FIG. 9, the shelf pressure control valve 86 provided in the middle of the forward clutch oil passage 82 has the forward clutch oil passage 82, which is the supply-side forward clutch oil passage 82A and the output-side forward clutch. The spool valve body 94 is provided slidably inside the sliding hole 92 of the valve main body 90 so as to be separated from the oil passage 82B.

In the valve body 90, a supply port 126 that communicates with the manual valve 78 that is the hydraulic oil supply side by the supply-side forward clutch oil passage 82A and opens into the sliding hole 92, and the sliding of this supply port 126. Sliding hole 92 on one side in the hole axis direction
There is provided one output port 128 communicating with the output side forward clutch oil passage 82B to the forward clutch 46 on the hydraulically operated friction engagement element side.

The spool valve element 94 is provided with a small diameter portion 130 which communicates the supply port 126 and the output port 128 at a central portion in the axial direction, and the small diameter portion 130 has first and second small diameter portions 130 on both sides in the axial direction of the spool valve element. The land portions 132 and 134 are provided, and these first and second land portions 132 and
The third land portion 136 is provided on the small diameter portion 130 between the portions 34.

The small-diameter portion 130 has a length L4 in the sliding hole axial direction between the space between the supply port 126 and the output port 128.
Has a longer length L5 in the axial direction of the spool valve body (L5
4 <> L5). The third land portion 136 has a length L7 in the spool valve body axial direction shorter than the length L6 in the sliding hole axial direction between the proximity portions of the supply port 126 and the output port 128 (L6> L7), An overlap margin L8 is formed and provided.

The small diameter section 130 connects the supply port 126 and the output port 128. The first land portion 132 blocks communication between the output port 128 and the first chamber 108 that is partitioned and formed on one side in the axial direction of the sliding hole 92 of the valve body 90.
The second land portion 134 and the supply port 1 and the second chamber 110 that is partitioned and formed on the other side in the axial direction of the sliding hole 92 of the valve body 90.
The communication with 26 is cut off. The third land portion 136 blocks communication between the supply port 126 and the output port 128 when the spool valve body 94 moves to the middle in the sliding hole axial direction.

In the second chamber 110 on the other side in the axial direction of the sliding hole,
A biasing force is applied to the spool valve body 94 so as to move the spool valve body 94 to a position where the supply port 126 and the output port 128 are communicated with each other by the small diameter portion 130 between the second land portion 134 and the third land portion 136. A spring 112 is provided as an urging means for urging.

In the first chamber 108 located on one side in the axial direction of the sliding hole,
One end of the feedback circuit 114, which communicates with the output-side forward clutch oil passage 82B, is provided with the other end thereof, and the feedback circuit 114 is provided with an orifice 116. The feedback circuit 114 moves the spool valve element 94 to a position where the supply port 126 and the output port 128 are cut off from communication by the third land portion 136, so that the output-side forward clutch oil passage 8 on the output port 128 side is moved.
The feedback pressure extracted from the hydraulic oil of 2B is applied to the first chamber 108, and the feedback pressure is applied to the first land portion 132 of the spool valve body 94 from one side in the sliding hole axial direction in the direction opposite to the biasing force of the spring 112. To act.

The shelf pressure control valve 86 has a supply port 126.
And the output port 128 are bypassed to provide a first bypass circuit 118 that communicates the supply-side forward clutch oil passage 82A and the output-side forward clutch oil passage 82B, and the orifice 120 is provided in the first bypass circuit 118. ing.

Further, the shelf pressure control valve 86 is connected to the supply port 126 and the output port 1 via the first bypass circuit 118.
28 and bypasses the supply side forward clutch oil passage 82.
A second connecting A and the output side forward clutch oil passage 82B
A bypass circuit 122 is provided, and the second bypass circuit 12 is provided.
2 is provided with a one-way valve 124 that allows the working oil to flow only from the output port 128 side to the supply port 126 side.

Next, the operation will be described.

In the automatic transmission 6, the driving force of the internal combustion engine 2 is relatively increased or decreased by increasing or decreasing the radius of gyration of the belt 18 wound around the driving pulley 14 and the driven pulley 16.
The gear ratio is continuously changed, and the forward clutch 46, which is a hydraulically operated friction engagement element of the forward / reverse switching mechanism 42, is used.
The power transmission path is switched between the forward drive and the reverse drive by engaging or releasing the reverse brake 48 and the reverse brake 48 with hydraulic oil.

The forward clutch 46 and the reverse brake 48, which are the hydraulically actuated friction engagement elements, have a shelf pressure control valve 86 for temporarily gradually increasing the pressure of the supplied hydraulic oil.
・ 88 is provided. The shelf pressure control valves 86 and 88 operate as follows.

The shelf pressure control valve 86 for temporarily gradually increasing the pressure of the hydraulic oil supplied to the forward clutch 46,
When the pressure of the hydraulic oil in the output-side forward clutch oil passage 82B is zero, as shown in FIG.
The spool valve element 94 is moved by the urging force of the spring 112 to a position on the one side in the sliding hole axial direction where the output port 128 and the output port 128 communicate with each other by the small diameter portion 130 between the second land portion 134 and the third land portion 136. ing.

The shelf pressure control valve 86 starts supplying the hydraulic oil in the supply side forward clutch oil passage 82A from time t1 in FIG. 2 in a state where the hydraulic oil pressure in the output side forward clutch oil passage 82B is zero. Then, the working oil flows from the supply port 126 to the output port 128 via the small diameter portion 130, and the working oil flows via the orifice 120 of the first bypass circuit 118, so that the pressure in the output side forward clutch oil passage 82B rises. To do.

The shelf pressure control valve 86 controls the rising pressure of the output side forward clutch oil passage 82B by the feedback circuit 114.
As a result, it acts as feedback pressure on the first chamber 108, and the spool valve element 94 gradually moves toward the other side in the sliding hole axial direction.

The spool valve element 94, which is moved toward the other side in the axial direction of the sliding hole, has the output side forward clutch oil passage 82B.
When the hydraulic oil of No. 3 further rises, as shown in FIG. 11, the communication between the supply port 126 and the output port 128 is established by the overlap margin L8 of the third land unit 136.
It is cut off by 36 (time t2 in FIG. 2).

As a result, the shelf pressure control valve 86 causes the spring 112 to move during the first period A of the hydraulic oil supply from the start of the supply of the time t1 in FIG. 2 to the time t2 when the output port 128 is closed.
The biasing force moves the spool valve element 94 to a position where the supply port 126 and the output port 128 are communicated with each other by the small diameter portion 130 between the second land portion 134 and the third land portion 136, and the pressure is rapidly increased.

As shown in FIG. 11, when the communication between the supply port 126 and the output port 128 is cut off by the third land portion 136, the shelf pressure control valve 86 causes the supply-side forward clutch oil passage 82A and the output-side forward passage. The orifice 12 of the first bypass circuit 118 according to the pressure difference with the clutch oil passage 82B.
The hydraulic oil flows only through 0, and the pressure in the output-side forward clutch oil passage 82B is gradually increased.

In the shelf pressure control valve 86, the gradually increasing pressure of the output side forward clutch oil passage 82B is acted as feedback pressure on the first chamber 108 by the feedback circuit 114, and the spool valve element 94 moves in the sliding hole axial direction. It is gradually moved toward the other side.

In the spool valve element 94 that is gradually moved toward the other side in the sliding hole axial direction, the hydraulic oil in the output side forward clutch oil passage 82B further rises, and as shown in FIG.
When the third land portion 136 moves to the supply port 126,
As shown in FIG. 13, the supply port 126 and the output port 12
8 is communicated with the small diameter portion 130 between the first land portion 132 and the third land portion 136 (time t3 in FIG. 2).

As a result, the shelf pressure control valve 86 moves to the middle period B of the hydraulic oil supply from the closing of the supply port 126 and the output port 128 at time t2 in FIG.
The spool valve element 94 is located at a position where the third land portion 136 blocks communication between the supply port 126 and the output port 128 due to the feedback pressure of the feedback circuit 114.
The orifice 12 of the first bypass passage 118.
When 0, the pressure rise is moderated to form a shelf pressure.

As shown in FIG. 13, when the supply port 126 and the output port 128 are in communication with each other, the shelf pressure control valve 86 is
The pressure in the output-side forward clutch oil passage 82B rises, the working oil flows from the supply port 126 to the output port 128 via the small diameter portion 130, and the working oil flows via the orifice 120 of the first bypass circuit 118, The pressure in the output-side forward clutch oil passage 82B increases.

The shelf pressure control valve 86 controls the rising pressure of the output side forward clutch oil passage 82B by the feedback circuit 114.
As a result, it acts as a feedback pressure on the first chamber 108, and the spool valve body 94 is moved toward the other side in the sliding hole axial direction.

The spool valve element 94, which is moved toward the other side in the sliding hole axial direction, has the output forward clutch oil passage 82B.
When the hydraulic oil in the second rises, the supply port 126 and the second
The communication ratio with the output port 128 is increased.

As a result, the shelf pressure control valve 86 is set to the position shown in FIG.
During the latter period C of supplying hydraulic oil from the time when the supply port 126 and the output port 128 communicate with each other at the time t3 until the time t4 when the set pressure is reached, the feed port 126 and the output port 128 are separated by the small diameter portion 130 by the feedback pressure of the feedback circuit 114. The spool valve element 94 is moved to the position where it is communicated with the pressure, and the pressure is rapidly increased. At time t4,
The supply pressure of the input side forward clutch oil passage 82A and the output pressure of the output side forward clutch oil passage 82B are matched.

On the other hand, the shelf pressure control valve 86 controls the supply port 12 when the hydraulic oil is discharged from the forward clutch 46.
Even if the communication between 6 and the output port 128 is blocked by the third land portion 136, as shown in FIG. 6 of the first embodiment,
The hydraulic oil flows through the orifice 120 of the first bypass circuit 118 and the one-way valve 124 of the second bypass circuit 122 to the input-side forward clutch oil passage 82A.

Thus, the shelf pressure control valve 86 bypasses the supply port 126 and the output port 128 by the one-way valve 124 of the second bypass circuit 122 when the hydraulic oil is discharged from the forward clutch 46. The input-side forward clutch oil passage 82A and the output-side forward clutch oil passage 82B are made to communicate with each other so that the pressure can be quickly reduced, and the shelf pressure is not formed.

As described above, the automatic transmission 6 supplies the hydraulic oil to the forward clutch 46 by the shelf pressure control valve 86 provided in the forward clutch oil passage 82 for supplying and discharging the hydraulic oil to the forward clutch 46. In the first half of the supply of hydraulic oil, the pressure is quickly increased, in the middle of the hydraulic oil supply, the pressure is gradually increased to form a shelf pressure, and in the latter half of the hydraulic oil supply, the pressure is rapidly increased. The pressure is rapidly reduced when the hydraulic oil is discharged from the forward clutch 46.

As a result, in the automatic transmission 6, the valve body 90 of the shelf pressure control valve 86, the spool valve body 94, the feedback circuit 114, and the first and second bypass passages 118.
The mechanical configuration of the orifices 22 and the one-way valve 124 of 22 makes it possible to easily form the shelf pressure.

Therefore, the automatic transmission 6 does not have an accumulator or an electrically controlled pressure regulating valve as in the conventional case, but has a shelf pressure for alleviating a shock generated when engaging the forward clutch 46. Can be formed by the shelf pressure control valve 86 having a simple structure. Further, in the automatic transmission 6, similarly, the shelf pressure for reducing the shock generated when the reverse brake 48 is engaged can be formed by the shelf pressure control valve 88 having a simple structure.

Therefore, the automatic transmission 6 does not have the problem of adversely affecting the layout of the hydraulic circuit and the shape of the transmission case, unlike the accumulator, and the apparent hydraulic oil consumption increases due to the increase in hydraulic oil consumption. It is possible to avoid disadvantages that are disadvantageous in terms of the oil balance of the system, and it is possible to eliminate the adverse effect on rapid gear shifting due to the orifice provided in the hydraulic circuit upstream of the accumulator.
Since it is not necessary to prepare various sensors and control algorithms like an electrically controlled pressure regulating valve, it can be implemented cost effectively.

14 and 15 show the third embodiment. In the third embodiment, parts having the same functions as those in the first embodiment will be described with the same reference numerals. In the automatic transmission 6 of the third embodiment, similarly to the first embodiment, the hydraulic circuit 68 of the shift control device 66 includes a shelf pressure control valve 86 for the forward clutch 46 of the forward / reverse switching mechanism 42 and a reverse pressure control valve 86. Brake 48
And the shelf pressure control valve 88 of FIG.

The shelf pressure control valve 86 provided in the middle of the forward clutch oil passage 82 has the same structure as that of the first embodiment, and therefore will be briefly described.

That is, in the shelf pressure control valve 86, as shown in FIG. 14, a spool valve body 94 is slidably provided inside a sliding hole 92 of a valve body 90, and a supply port 96 and a supply port 96 are provided in the valve body 90. The first and second sides of the supply port 96 on both sides in the sliding hole axial direction
Output ports 98 and 100 are provided, and the spool valve element 94 has a small diameter portion 102 and a first portion on both sides in the axial direction of the small diameter portion 102.
The second land portions 104 and 106 are provided.

The valve body 90 includes a second hole on the other side in the axial direction of the sliding hole.
A spring 112 is provided in the chamber 110, a feedback circuit 114 that connects the first chamber 108 on one side in the sliding hole axial direction with the output-side forward clutch oil passage 82B is provided, and the feedback circuit 114 is provided with an orifice 116.

The shelf pressure control valve 86 is provided with an orifice 120 in a first bypass circuit 118 which connects the supply-side forward clutch oil passage 82A and the output-side forward clutch oil passage 82B, and the first bypass circuit. A one-way valve 124 is provided in a second bypass circuit 122 that connects the supply-side forward clutch oil passage 82A and the output-side forward clutch oil passage 82B via 118.

The shelf pressure control valve 86 includes a spring 112.
A signal pressure generating means 138 for applying a signal pressure to the urging force is provided. The signal pressure generating means 138 is composed of, for example, an electromagnetic valve or the like, and its operation is controlled by the shift control means 80.

The signal pressure generating means 138 controls the spring 1 when the hydraulic oil is supplied to the forward clutch 46.
The hydraulic fluid of the signal pressure taken out from the hydraulic circuit 68 is supplied to the second chamber 110 on the other side in the axial direction of the sliding hole of the valve body 90 provided with 12, while being changed according to the shift state of the automatic transmission 6 and the like. To do.

As a result, the shelf pressure control valve 86 differs due to the signal pressure generating means 138 for the biasing force of the spring 112 with respect to the feedback pressure of the feedback circuit 114 during the middle supply period when the hydraulic oil is supplied to the forward clutch 46. By adding the signal pressure of the pressure, as shown in FIG.
Different levels of shelf pressure can be created.

For this reason, the automatic transmission 6 can be formed by finely controlling the shelf pressure for alleviating the shock generated when the forward clutch 46 is engaged,
The shock can be precisely mitigated.

FIG. 16 shows the fourth embodiment.
In the fourth embodiment, parts having the same functions as those in the first embodiment will be described with the same reference numerals. In the automatic transmission 6 according to the fourth embodiment, as in the first embodiment, the forward clutch 4 of the forward / reverse switching mechanism 42 is provided in the hydraulic circuit 68 of the shift control device 66.
A shelf pressure control valve 86 for the No. 6 and a shelf pressure control valve 88 for the reverse brake 48 are provided so as to be interposed.

The shelf pressure control valve 86 provided in the middle of the forward clutch oil passage 82 is constructed in the same manner as in the first embodiment, and therefore its outline will be described.

That is, in the shelf pressure control valve 86, a spool valve body 94 is slidably provided inside a sliding hole 92 of a valve body 90, and a supply port 96 and this supply port 96 are provided in the valve body 90.
Sliding hole of the first and second output ports 98.1 on both sides in the axial direction
00, the small diameter portion 102 and the first and second land portions 10 on both sides in the axial direction of the small diameter portion 102 are provided on the spool valve element 94.
4 and 106 are provided.

The valve body 90 has a second hole on the other side in the axial direction of the sliding hole.
A spring 112 is provided in the chamber 110, a feedback circuit 114 that connects the first chamber 108 on one side in the sliding hole axial direction with the output-side forward clutch oil passage 82B is provided, and the feedback circuit 114 is provided with an orifice 116.

The shelf pressure control valve 86 is provided with a bypass circuit 140 that connects the supply-side forward clutch oil passage 82A and the output-side forward clutch oil passage 82B, and operates only on the supply port 96 side in the bypass circuit 140. A one-way valve 142 that allows oil to flow is provided.

The shelf pressure control valve 86 connects the supply port 96 and the first and second output ports to the first and second communication ports, respectively.
The first and second orifices 144, which slightly connect the supply port 96 and the first and second output ports via the small diameter portion 102 when the land portions 104 and 106 are shut off from each other.
146 are formed in a groove shape at radially symmetrical positions of the ends of the first and second lands 104 and 106 on the side of the small diameter portion 102.

As a result, in the shelf pressure control valve 86, the communication between the supply port 96 and the first and second output ports 98 and 100 is first during the middle supply period when the hydraulic oil is supplied to the forward clutch 46. When the second land portions 104 and 106 are disconnected, the first and second first and second corresponding to the pressure difference between the supply-side forward clutch oil passage 82A and the output-side forward clutch oil passage 82B.
The first and second orifices 144 of the land portions 104 and 106
Since the hydraulic oil flows only through 146 and the pressure in the output side forward clutch oil passage 82B is gradually increased, the increase in pressure can be moderated to form the shelf pressure.

Therefore, the automatic transmission 6 does not require the first bypass circuit 118 and the orifice 120 of the first embodiment, and the first and second orifices formed in the first and second land portions 104 and 106. With 144 and 146, it is possible to form a shelf pressure for alleviating the shock that occurs when the forward clutch 46 is engaged, so that the shock can be alleviated precisely, and the number of parts and processing man-hours can be reduced. The cost can be reduced.

FIG. 17 shows the fifth embodiment.
In the fifth embodiment, parts having the same functions as those in the first embodiment will be described with the same reference numerals. In the automatic transmission 6 of the fifth embodiment, as in the first embodiment, the forward clutch 4 of the forward / reverse switching mechanism 42 is provided in the hydraulic circuit 68 of the shift control device 66.
A shelf pressure control valve 86 for the No. 6 and a shelf pressure control valve 88 for the reverse brake 48 are provided so as to be interposed.

The shelf pressure control valve 86 provided in the middle of the forward clutch oil passage 82 is constructed in the same manner as in the first embodiment, and therefore its outline will be described.

That is, in the shelf pressure control valve 86, the spool valve body 94 is slidably provided in the sliding hole 92 of the valve body 90, and the supply port 96 and the supply port 96 are provided in the valve body 90.
Sliding hole of the first and second output ports 98.1 on both sides in the axial direction
00, the small diameter portion 102 and the first and second land portions 10 on both sides in the axial direction of the small diameter portion 102 are provided on the spool valve element 94.
4 and 106 are provided.

The valve body 90 includes the second hole on the other side in the axial direction of the sliding hole.
A spring 112 is provided in the chamber 110, a feedback circuit 114 that connects the first chamber 108 on one side in the sliding hole axial direction with the output-side forward clutch oil passage 82B is provided, and the feedback circuit 114 is provided with an orifice 116.

The shelf pressure control valve 86 is used for the forward clutch 4
Supply port 96 in the middle supply period when supplying hydraulic oil to 6
When the communication between the first and second output ports is blocked by the first and second land parts 104 and 106, respectively, the supply port 96 and the first and second output ports are connected via the small diameter part 102. First and second orifices 144, 14 that are slightly in communication
6 are formed in a groove shape at radially symmetrical positions of the ends of the first and second land portions 104 and 106 on the side of the small diameter portion 102.

The shelf pressure control valve 86 is provided in the first chamber 10
8 and the supply-side forward clutch oil passage 82A are provided with a bypass circuit 148, and the one-way valve 1 that allows the hydraulic oil to flow only to the supply port 96 side in the bypass circuit 148.
50 are provided.

As a result, the shelf pressure control valve 86 allows the communication between the supply port 96 and the first and second output ports 98 and 100 to be the first in the middle of the supply when the hydraulic oil is supplied to the forward clutch 46. When the second land portions 104 and 106 are disconnected, the first and second first and second corresponding to the pressure difference between the supply-side forward clutch oil passage 82A and the output-side forward clutch oil passage 82B.
The first and second orifices 144 of the land portions 104 and 106
Since the hydraulic oil flows only through 146 and the pressure in the output side forward clutch oil passage 82B is gradually increased, the increase in pressure can be moderated to form the shelf pressure.

Further, in this shelf pressure control valve 86, when the hydraulic oil is discharged from the forward clutch 46, even if the supply port 96 and the first and second output ports 98 and 100 are the first and second land portions, Even if the communication is blocked by 104 and 106, the first chamber 10 is connected through the one-way valve of the bypass circuit 148.
8 flows into the input side forward clutch oil passage 82A, and the spool valve element 94 is moved toward one side in the sliding hole axial direction, so that the first output port 98 and the supply port 86
The pressure can be quickly dropped by communicating with and the shelf pressure is not formed.

Therefore, the automatic transmission 6 does not require the first bypass circuit 118 and the orifice 120 of the first embodiment, and the first and second orifices formed in the first and second land portions 104 and 106. With 144 and 146, it is possible to form a shelf pressure for alleviating the shock that occurs when the forward clutch 46 is engaged, so that the shock can be alleviated precisely, and the number of parts and processing man-hours can be reduced. The cost can be reduced, and the bypass circuit 148 and the one-way valve 150 can be used when the hydraulic oil is discharged.
With this, the pressure can be quickly dropped, and the spool valve element 94 can be returned to the initial position.

[0116]

As described above, in this automatic transmission, the shelf pressure is formed by the mechanical structure of the valve body of the shelf pressure control valve, the spool valve body, the feedback circuit, the orifice of the bypass passage, and the one-way valve. be able to.

As a result, this automatic transmission has no accumulator or electrically controlled pressure regulating valve.
The shelf pressure for alleviating the shock generated when the hydraulically actuated friction engagement element is fastened can be formed by the shelf pressure control valve having a simple structure. For this reason, this automatic transmission does not cause problems such as the accumulator that adversely affects the handling of the hydraulic circuit and the shape of the transmission case, and the apparent increase in hydraulic oil consumption increases the oil amount in the hydraulic circuit system. It is possible to avoid disadvantages that are disadvantageous in terms of income and expenditure, and
It is possible to eliminate the adverse effect on rapid speed change due to the orifice provided in the hydraulic circuit upstream of the accumulator, further, it is not necessary to prepare various sensors and control algorithms like an electrically controlled pressure regulating valve, It can be implemented cost effectively.

[Brief description of drawings]

FIG. 1 is a sectional view of a shelf pressure control valve showing a first embodiment of a change of an automatic transmission.

FIG. 2 is a time chart showing changes in pressure.

FIG. 3 is a cross-sectional view of a shelf pressure control valve showing a state of a supply early period when supply of hydraulic oil is started.

FIG. 4 is a cross-sectional view of the shelf pressure control valve showing a state in a middle supply period in which shelf pressure is being formed.

FIG. 5 is a cross-sectional view of the shelf pressure control valve showing a state in the latter half of supply when the pressure reaches a set value.

FIG. 6 is a cross-sectional view of the shelf pressure control valve showing a state where hydraulic oil is being discharged.

FIG. 7 is a sectional view of an automatic transmission.

FIG. 8 is a diagram showing a hydraulic circuit of the shift control device.

FIG. 9 is a sectional view of a shelf pressure control valve showing a second embodiment.

FIG. 10 is a cross-sectional view of the shelf pressure control valve showing the state of the first half of the period when the supply of hydraulic oil has started.

FIG. 11 is a cross-sectional view of the shelf pressure control valve showing a start state of a middle supply period in which shelf pressure is being formed.

FIG. 12 is a cross-sectional view of the shelf pressure control valve showing an end state in the middle supply period in which shelf pressure is being formed.

FIG. 13 is a cross-sectional view of the shelf pressure control valve showing a state in the latter half of supply when the pressure reaches a set value.

FIG. 14 is a sectional view of a shelf pressure control valve showing a third embodiment.

FIG. 15 is a time chart showing changes in pressure.

FIG. 16 is a sectional view of a shelf pressure control valve showing a fourth embodiment.

FIG. 17 is a sectional view of a shelf pressure control valve showing a fifth embodiment.

[Explanation of symbols]

2 Internal combustion engine 6 automatic transmission 42 Forward / reverse switching mechanism 44 oil pump 46 Forward clutch 48 reverse brake 66 Shift control device 68 Hydraulic circuit 70 line pressure oil passage 72 Line pressure regulator 74 Clutch pressure oil passage 76 Clutch pressure regulator 78 Manual valve 80 Shift control means 82 Forward clutch oil passage 82A Supply side forward clutch oil passage 82B Output side forward clutch oil passage 84 Reverse brake oil passage 86/88 Shelf pressure control valve 90 valve body 92 Sliding hole 94 spool valve body 96 supply port 98 First output port 100 Second output port 102 Small diameter part 104 First Land 106 Second Land Part 112 spring 114 Feedback circuit 118 First Bypass Circuit 120 orifice 122 Second Bypass Circuit 124 One-way valve

Claims (4)

[Claims] 1. An automatic transmission that shifts a power transmission path by engaging or releasing a hydraulically actuated frictional engagement element to shift gears, and a rack in an oil passage for supplying and discharging hydraulic oil to the hydraulically actuated frictional engagement element. A pressure control valve is provided, and this shelf pressure control valve is provided with a spool valve body slidably provided in a sliding hole of a valve body, and a supply port and an output port communicating with the sliding hole are provided in the valve body. A small diameter portion is provided on the spool valve element and a land portion is provided, and a biasing force is applied to the spool valve element so as to move the spool valve element to a position where the supply port and the output port are communicated with each other by the small diameter portion. A urging means for acting is provided, and a feed bar extracted from the hydraulic oil on the output port side so as to move the spool valve element to a position where the land portion blocks the communication between the supply port and the output port. A feedback circuit that applies a lock pressure to the spool valve element is provided, and an orifice is provided in a bypass circuit that bypasses the supply port and the output port and connects the oil passage, and operates only from the output port side to the supply port side. A one-way valve that allows oil to flow is provided, and the supply port and the output port communicate with each other through the small-diameter portion by the urging force of the urging means in the first half of the period when the hydraulic oil is supplied to the hydraulically actuated friction engagement element. The position at which the supply port and the output port are cut off from the communication by the feedback pressure of the feedback circuit during the middle period of the supply of the hydraulic oil by moving the spool valve element to the position The spool valve element is moved to the above position and the orifice of the bypass passage moderates the rise in pressure to form a shelf pressure. In the latter half of oil supply, the spool valve element is moved to a position where the feed port and the output port communicate with each other by the small diameter portion by the feedback pressure of the feedback circuit until the set value is reached, so that the pressure is rapidly increased, and When the hydraulic oil is discharged from the operating frictional engagement element, the one-way valve of the bypass circuit bypasses the supply port and the output port to connect the oil passage to rapidly reduce the pressure. Automatic transmission. 2. An automatic transmission that shifts power by switching a power transmission path by engaging or disengaging a hydraulically actuated frictional engagement element, and a rack in an oil passage for supplying and discharging hydraulic oil to the hydraulically actuated frictional engagement element. A pressure control valve is provided, and this shelf pressure control valve is provided with a spool valve body slidably installed in the sliding hole of the valve body, and communicates with the hydraulic oil supply side of the valve body and into the sliding hole. The spool valve is provided with a supply port that opens and first and second output ports that respectively communicate with the hydraulically actuated friction engagement element side by opening in the slide holes on both sides of the slide port in the axial direction of the supply port. The body is provided with a small-diameter portion that selectively communicates the supply port and one of the first and second output ports, and the supply port and the second output port are provided on one side of the small-diameter portion in the spool valve body axial direction. Block the communication with the 1st output port when communicating A second land portion provided with the first land portion and blocking the communication with the second output port when the supply port and the first output port communicate with each other on the other side in the axial direction of the spool valve body.
A land portion is provided, and the biasing means for exerting a biasing force on the spool valve body so as to move the spool valve body to a position where the supply port and the first output port communicate with each other by the small diameter portion is provided in the sliding hole axis line. The first and second outputs are provided on the other side in the direction so as to move the spool valve element to a position where the communication between the supply port and the first and second output ports is blocked by the first and second lands. A feedback circuit is provided which causes the feedback pressure extracted from the hydraulic oil on the port side to act on the spool valve element from one side in the sliding hole axial direction in the direction opposite to the urging force of the urging means. A first bypass circuit that bypasses the second output port and communicates with the oil passage is provided, and an orifice is provided in the first bypass circuit, and the supply port and the first
A second bypass circuit that bypasses the second output port and communicates with the oil passage is provided, and the second bypass circuit allows the working oil to flow only from the first and second output port sides to the supply port side. A one-way valve is provided so that the supply port and the first output port are communicated with each other by the small-diameter portion by the urging force of the urging means in the first half of the period of supplying the hydraulic oil to the hydraulically-actuated friction engagement element. The spool valve element is moved to rapidly increase the pressure, and the feed port and the first and second output ports are connected by the first and second lands by the feedback pressure of the feedback circuit in the middle of the supply of the hydraulic oil. The spool valve element is moved to a position where communication is cut off, the rise of pressure is moderated by the orifice of the first bypass passage to form a shelf pressure, and the shelf pressure is set at a later stage of the hydraulic oil supply. Until the value is reached, the spool valve element is moved to a position where the supply port and the second output port are communicated with each other by the small diameter portion by the feedback pressure of the feedback circuit to rapidly increase the pressure, and the hydraulically actuated friction engagement element. When the hydraulic oil is discharged from the pump, the one-way valve of the second bypass circuit bypasses the supply port and the first and second output ports to connect the oil passage to rapidly reduce the pressure. The automatic transmission according to claim 1. 3. An automatic transmission that shifts power by switching a power transmission path by engaging or releasing a hydraulically operated frictional engagement element, and a rack in an oil passage for supplying and discharging hydraulic oil to the hydraulically operated frictional engagement element. A pressure control valve is provided, and this shelf pressure control valve is provided with a spool valve body slidably installed in the sliding hole of the valve body, and communicates with the hydraulic oil supply side of the valve body and into the sliding hole. A supply port that opens and an output port that communicates with the hydraulically actuated friction engagement element side by opening in the sliding hole on one side in the sliding hole axial direction of the supply port are provided, and the supply port is provided in the spool valve body. And a small diameter portion that communicates with the output port are provided, and first and second lands are provided on both sides of the small diameter portion in the spool valve body axial direction, and the spool valve is provided in the small diameter portion between the first and second lands. The body moved to the middle of the sliding hole axial direction At this time, a third land portion is provided to block the communication between the supply port and the output port, and the spool is provided at a position where the supply port and the output port are communicated with each other by the small diameter portion between the second land portion and the third land portion. A biasing means for exerting a biasing force on the spool valve body to move the valve body is provided on the other side in the axial direction of the sliding hole, and the communication between the supply port and the output port is blocked by the third land portion. The feedback pressure extracted from the hydraulic oil on the output port side to move the spool valve element is applied to the spool valve element from one side in the axial direction of the sliding hole in the direction opposite to the urging force of the urging means. And a first bypass circuit for communicating the oil passage by bypassing the supply port and the output port and providing an orifice in the first bypass circuit. A second bypass circuit that bypasses the supply port and the output port and communicates the oil passage is provided, and the second bypass circuit allows the working oil to flow only from the output port side to the supply port side. When a directional valve is provided and the hydraulic oil is supplied to the hydraulically actuated friction engagement element, the supply port and the output port are located between the second land portion and the third land portion due to the urging force of the urging means in the first period of supply. The spool valve element is moved to a position communicated by the small diameter portion to quickly increase the pressure,
During the middle period of the supply of the hydraulic oil, the spool valve element is moved to a position where the communication between the supply port and the output port is blocked by the third land portion by the feedback pressure of the feedback circuit, and the orifice of the first bypass passage is used. The pressure rise is moderated to form a shelf pressure, and the supply port and the output port are connected to the first land portion and the second land portion by the feedback pressure of the feedback circuit until the set value is reached in the latter period of the hydraulic oil supply. The one-way valve of the second bypass circuit is used when the spool valve element is moved to a position communicated by the small-diameter portion between them to rapidly increase the pressure and discharge hydraulic oil from the hydraulically actuated friction engagement element. The pressure is rapidly reduced by bypassing the supply port and the output port with each other to connect the oil passages with each other. Automatic transmission. 4. The shelf pressure control valve is provided with a signal pressure generating means for applying a signal pressure to the urging force of the urging means, and during the middle supply period when supplying hydraulic oil to the hydraulically operated friction engagement element. 4. The rack pressures of different heights are formed by adding the signal pressure of the signal pressure generating means to the biasing force of the biasing means with respect to the feedback pressure of the feedback circuit. The automatic transmission according to any one.