JPH064065Y2 - Variable capacity oblique shaft type hydraulic rotary machine - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to improvement of a variable displacement type oblique shaft type hydraulic rotary machine as a hydraulic pump and hydraulic motor used in civil engineering / construction machinery and other general machines.

[Conventional technology]

3 and 4 show a hydraulic pump as a displacement type oblique shaft type hydraulic rotary machine according to the prior art.

In the figure, 1 is a tubular casing, and the casing 1
Is a substantially cylindrical casing body 1 with one end serving as a bearing portion
A and a head casing 1B that closes the other end of the casing body 1A. 2 is the casing body 1
A rotary shaft 3 rotatably projected in A is a cylinder block located in the casing body 1A and rotating together with the rotary shaft 2. The cylinder block 3 has a plurality of cylinders 4 in its axial direction. Has been drilled. Each cylinder 4
A piston 5 is slidably provided therein, and a connecting rod 6 is attached to each piston 5. A spherical portion 6A is formed at the tip of each connecting rod 6, and the spherical portion 6A is swingably supported by a drive disk 7 formed at the tip of the rotary shaft 2.

Reference numeral 8 denotes a valve plate. One end face of the valve plate 8 is in sliding contact with the cylinder block 3, and the other end face is slidable on a tilted sliding surface 9 formed in the head casing 1B and having a concave arc shape. The valve plate 8 is provided with a through hole 8A at the center thereof, into which the tip ends of a center shaft 10 and a swing pin 15, which will be described later, are inserted from both sides. The valve plate 8 is provided with a pair of supply / discharge ports (not shown) which are intermittently communicated with the cylinders 4 by the rotation of the cylinder block 3, and the supply / discharge ports are inclined with respect to the valve plate 8. The head casing 1B communicates with a supply / discharge passage (not shown) that opens to the tilting sliding surface 9 regardless of the rolling position.

Reference numeral 10 is a center shaft for supporting the cylinder block 3 between the drive disk 7 and the valve plate 8. The center shaft 10 has a spherical portion 10A formed on one end side thereof.
The spherical portion 10A is swingably supported at the axial center position of the drive disk 7. On the other hand, the other end of the center shaft 10 protruding through the center of the cylinder block 3 is slidably inserted into the through hole 8A of the valve plate 8 to center the cylinder block 3 and the valve plate 8. Has been.

Reference numeral 11 denotes a tilting mechanism for tilting the valve plate 8 along the tilt sliding surface 9 between the maximum tilt side and the minimum tilt side.
Is bored in the head casing 1B, has a cylinder chamber 12 having oil passage holes 12A and 12B at both axial ends thereof, and is slidably inserted into the cylinder chamber 12, and both sides of the cylinder chamber 12 in the axial direction are subjected to hydraulic pressure. From the servo piston 14 that defines the chambers 13A and 13B, and the swing pin 15 that is inserted into the peripheral body portion of the servo piston 14 and has the spherical tip portion 15A swingably inserted into the through hole 8A of the valve plate 8. Composed and plumbing 16
A tilting drive is performed by an auxiliary pump 17 that supplies pressure oil for tilting into the hydraulic chambers 13A, 13B from the oil passage holes 12A, 12B via A, 16B. In addition, 1 in the figure
Reference numeral 8 is a tank connected to the pipe 16B.

A control unit 19 is provided outside the head casing 1B for controlling the tilting mechanism 11. The control unit 19 is located between the auxiliary pump 17 and the cylinder chamber 12 and is located in the middle of the pipes 16A and 16B. The throttle switch valve 20 is provided in the control valve 20 and is capable of feedback-controlling the pilot pressure of the pressure oil from the auxiliary pump 17 by the sleeve 20A, and the operation lever 21 for switching the throttle switch valve 20. Then, the sleeve 20A and the servo piston 14
Is connected to the servo piston 14 by a feedback pin 22 inserted into an elongated hole 1C formed in the head casing 1B, and the sleeve 20A is displaced by the auxiliary piston 17 as the servo piston 13 is displaced.
The pilot pressure of the pressure oil supplied to each of the hydraulic chambers 13A and 13B is controlled.

The variable displacement oblique shaft type hydraulic rotary machine according to the prior art has the above-mentioned configuration. Next, the operation of the hydraulic rotary machine as a hydraulic pump will be described.

First, the tilting mechanism 11 tilts the valve plate 8 together with the cylinder block 3 to the tilting position shown in the figure. Therefore, the operation lever 21 of the control unit 19 is operated to switch the throttle switching valve 20, the pressure oil from the auxiliary pump 17 is supplied to the hydraulic chamber 13A (13B) on one side of the cylinder chamber 12, and the servo piston 14 is operated. To displace. Then, the swing pin 15 is displaced together with the servo piston 14, and the valve plate 8 is tilted while sliding on the tilt sliding surface 9, so that the cylinder block 3 is also tilted and its rotation center axis is It is tilted with respect to the center axis of rotation of the rotary shaft 2 and is in the maximum tilted state shown.

Next, the drive source such as the engine and the electric motor is rotated to rotate the rotary shaft 2
When the rotary drive is performed, the drive disk 7 of the rotary shaft 2 and each piston 5 inserted in the cylinder 4 of the cylinder block 3
The cylinder block 3 is rotated together with the rotating shaft 2 because the connecting rod 6 is connected between the cylinder block 3 and the cylinder. Then, each piston 5 reciprocates in the cylinder 4 while the cylinder block 3 is rotating. When the pistons 5 are opposed to each other from the inside of the cylinder 4, the suction stroke for sucking the working oil from the supply / discharge passage into the cylinder 4 through the supply / discharge port is reached. 4 is a discharge stroke in which the hydraulic oil in 4 is pressurized and discharged from the supply / discharge passage via the supply / discharge port.

Then, during the operation of the hydraulic rotating machine described above, the tilt amount of the valve plate 8 is transmitted to the sleeve 20A of the throttle switching valve 20 via the feedback pin 22 integrally provided on the other side of the swing pin 15. . From the auxiliary pump 17 to each hydraulic chamber 13A (13
The pilot pressure of the pressure oil to B) is feedback-controlled by the sleeve 20A, and the flow rate of the pressure oil supplied to each hydraulic chamber 13A (13B) is controlled by following the tilt amount of the valve plate 8.

[Problems to be solved by the invention]

Thus, in the prior art configured as described above, the valve plate 8 sliding on the tilting sliding surface 9 makes an arc motion, while the servo piston 14 moves vertically in the cylinder chamber 12. Exercise. Therefore, the spherical tip portion 15A of the swing pin 15 fixed to the servo piston 14 performs a sliding action in the through hole 8A of the valve plate 8, but the swing pin 15 slides smoothly in the through hole 8A. In order to achieve this, it is necessary to provide a slight gap between the tip end portion 15A of the swing pin 15 and the through hole 8A. Then, the gap is enlarged due to abrasion due to the sliding action while the hydraulic rotary machine is operated for a long time.

Thus, an error occurs between the actual tilted position of the valve plate 8 due to the clearance and the position of the valve plate 8 detected by the feedback pin 22 via the swing pin 15, so that the sleeve of the throttle switching valve 20. There is a drawback in that the responsiveness of 20A is poor, the tracking accuracy of the throttle switching valve 20 is poor, and the feedback control performance is significantly reduced.

The feedback pin 22 that transmits the tilt amount A ₀ of the valve plate 8 to the control unit 19 is directly provided on the servo piston 14 that tilts the valve plate 8, and the displacement amount of the servo piston 14 and the feedback pin 22. Since the amount of displacement is the same, the control unit 19 cannot be provided on the casing body 1A side or cannot be made compact.

The present invention has been made in view of the above-mentioned problems of the prior art. Instead of indirectly detecting the tilting position of the valve plate from the tilting mechanism, the tilting amount is proportionally reduced from the valve plate. In this state, the variable displacement type oblique shaft type hydraulic rotary machine is designed to be able to detect directly in the closed state, thereby improving the response performance of the control unit, the response accuracy such as tracking accuracy, and the downsizing of the entire device. The purpose is to provide.

[Means for solving problems]

In order to solve the above problems, the feature of the means adopted by the present invention is that the tilting mechanism supplies and discharges pressure oil for tilting control.
A control unit which is located on the minimum tilt side of the valve plate and is provided in the peripheral body of the casing, one end of which is rotatably supported via a support pin on the control unit side and the other end of which is inside the casing. A projecting interlocking link, a swinging link having one end rotatably connected to the other end of the interlocking link, and the other end rotatably supported by a side surface portion of the valve plate via a detection pin, It is composed of an output pin provided on the interlocking link in order to feed back to the control section in a state where the tilt amount of the valve plate is proportionally reduced.

[Operation] As described above, the interlocking link is provided on the control unit side through the support pin, and the swing link is provided on the valve plate through the detection pin to connect with the interlocking link. The tilt amount of the plate can be directly detected as the swing amount of the swing link of the interlocking link. Moreover, since the output pin is provided in the interlocking link, the ratio r / R of the length R from the tilt center of the cylinder block to the detection pin and the length r from the support pin to the output pin is defined as The tilt amount can be output to the control unit in a state where the tilt amount is proportionally reduced.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to FIGS. 1 and 2. In addition, the same components as those of the above-described conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 31 is a casing according to the present embodiment, which comprises a cylindrical casing body 31A having an opening 32 and a head casing 31B for closing the other end of the casing body 31A. Here, the opening 32 is opened on the upper side of the peripheral body portion of the casing body 31A so as to be located on the minimum tilt side of the cylinder block 3 or the valve plate 8. It should be noted that the head casing 31B of this embodiment is not provided with the elongated hole 1C as shown in FIG.

A housing 33 is provided on the upper side of the peripheral body of the casing main body 31A so as to cover the opening 32 in order to accommodate a throttle switching valve (not shown) that constitutes the control unit 34 of the tilting mechanism 11. An operating lever (not shown) for operating the throttle switching valve is provided outside the housing 33.

Reference numeral 35 denotes a link mechanism as a feedback mechanism provided between the housing 33 and the valve plate 8. The link mechanism 35 is located at a distance R from the tilting center point 0 of the cylinder block 3 in the radial direction of the valve plate 8. Detecting pins 36 and 36 that are tiltably provided on both sides, and a housing 33 whose upper end accommodates the control unit 34.
An interlocking link 38 that is rotatably provided on the inner upper side via a support pin 37 and has a lower end protruding into the casing 31 from the opening 32, and an intermediate side to a lower side branch in an arc shape so as to straddle the cylinder block 3, A swinging link 40, each tip of which is fixed to each of the detection pins 36, and an upper side of which is rotatably connected to a lower end of the interlocking link 38 via a connection pin 39,
It is composed of an output pin 41 which is provided laterally in the middle of the interlocking link 38 at a position of a distance r from the center of the support pin 37 and whose tip is connected to the sleeve of the throttle switching valve.

The present embodiment is configured as described above, and there is no difference in the operation itself as the variable displacement hydraulic pump from that of the above-described conventional technique.

Therefore, in order to change the discharge capacity of the hydraulic pump, the operation lever of the control unit 34 is operated to switch the throttle switching valve,
When the pilot pressure of the pressure oil supplied from the auxiliary pump to each of the hydraulic chambers 13A and 13B is changed, the servo piston 14 is displaced in the cylinder chamber 12, resulting in the servo piston 1
The valve plate 8 is tilted while sliding on the tilting sliding surface 9 by the swing pin 15 which is displaced integrally with the valve plate 4.

As described above, the valve plate 8 is moved by the tilting mechanism 11 to the tilt sliding surface 9
When tilting while sliding on the top, the swing link 40 and the interlocking link 38 connected to the swing link 40 are connected to each other through a detection pin 36, 36 provided on the valve plate 8 as one point in FIG. Interlock as shown by the chain line. As a result, the output pin 41 swings with the moving amount A ₁ reduced to the ratio r / R with respect to the tilting amount A ₀ of the valve plate 8 to operate the sleeve of the throttle switching valve.

As described above in detail, according to the present embodiment, the tilt position of the valve plate 8 is directly detected by the detection pins 36, 36 protruding from the valve plate 8. There is no deviation in the follow-up control of the control unit 34 with respect to, and the control performance of the control unit 34 such as responsiveness, follow-up accuracy, and operation feeling is improved.

Further, the tilt amount A ₀ of the valve plate 8 is determined by the distance R from the tilt center point 0 of the cylinder block 3 to the detection pin 36 and the support pin 3
By appropriately setting the ratio of the distance r from the output pin 41 to the output pin 41, the tilt amount A ₀ can be reduced and transmitted to the control unit 34, so that the control unit 34 itself has more design freedom, and The miniaturization becomes possible.

Further, since the housing 33 of the control unit 34 can be provided on the minimum tilt side of the valve plate 8 and provided outside the body of the casing body 31A, the dead space generated on the minimum tilt side of the casing body 31 can be effectively used. As a result, the interlocking link 38 and the swinging link 40 can be arranged, so that the entire hydraulic rotary machine can be made compact and compact, and the degree of freedom in design can be increased. Moreover, although the tilt axis type hydraulic rotary machine has a disadvantage that the axial length becomes long, the axial length can be shortened by providing the control unit 34 in the body portion of the casing body 31A. The entire hydraulic rotary machine can be downsized.

[Effect of device]

Since the present invention is configured as described above in detail, the following effects can be achieved.

A control unit is provided on the peripheral body of the casing, and an interlocking link is provided on the control unit side via a support pin, and a swinging link is provided on the valve plate via a detection pin to connect with the interlocking link. Since the link is provided with an output and the tilt amount of the valve plate is derived from the output pin, the tilt amount of the valve plate can be directly detected from the valve plate and fed back to the control unit. It is possible to detect an accurate tilt amount and improve control performance.

The tilting amount of the valve plate is determined by the distance R from the tilting center of the cylinder block to the detection pin by the interlocking link and the swinging link.
And a configuration in which it is proportionally reduced according to the ratio of the distance r from the support pin to the output pin and transmitted to the control unit,
The control unit can be made compact and the degree of freedom in designing the control unit is increased.

In relation to the above item, since it is possible to feed back from the output pin to the control unit in a state where the tilt amount of the valve plate is proportionally reduced, the moving amount of the output pin is compared with the tilt amount of the valve plate. The size of the control unit can be reduced as much as possible, and the control unit can be downsized.

Since the control part is the peripheral body part of the casing and can be installed on the minimum tilt side, the axial length of the oblique shaft type hydraulic rotating machine can be shortened and the dead space in the casing is used to interlock. Since the link and the swing link can be provided, the size and size of the entire hydraulic rotating machine can be reduced.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention, FIG. 1 is a vertical sectional view of an oblique shaft type hydraulic rotary machine according to this embodiment, and FIG. 2 is a II-II arrow in FIG. Sectional views, FIG. 3 and FIG. 4 show the prior art, FIG. 3 is a vertical sectional view of the oblique shaft type hydraulic rotary machine according to the prior art, and FIG. 4 is a circuit diagram showing a tilting mechanism control circuit. is there. 2 ... Rotary axis, 3 ... Cylinder block, 4 ... Cylinder, 5
... Piston, 6 ... Connecting rod, 7 ... Drive disk, 8 ... Valve plate, 9 ... Tilt sliding surface, 11 ... Tilt mechanism, 31 ... Casing, 31B ... Head casing, 3
4 ... control part, 35 ... feedback mechanism, 36 ... detection pin, 37 ... support pin, 38 ... interlocking link, 40 ... rocking link, 41 ... output pin.

Claims (1)

[Scope of utility model registration request] 1. A cylindrical casing having an end surface closed by a head casing, a rotary shaft projecting rotatably in the casing, and a tip end of the casing serving as a drive disk, and a casing provided in the casing. A cylinder block rotating with the rotary shaft, a plurality of cylinders bored in the axial direction of the cylinder block, a piston slidably provided in each cylinder, and attached to each piston, A connecting rod whose tip is a spherical portion and is swingably supported by the drive disk of the rotary shaft, and one end face of which is in sliding contact with the cylinder block and the other end face of which is a tilted sliding face of the head casing. A valve plate slidably slidably provided with a pair of supply / discharge ports which are intermittently communicated with the cylinders while the cylinder block is rotating; A variable displacement oblique shaft type hydraulic rotating machine including a tilting mechanism provided in the head casing for tilting the valve plate together with the cylinder block, wherein the tilting mechanism uses pressure oil for tilting control. To feed and
A control unit which is located on the minimum tilt side of the valve plate and is provided in the peripheral body of the casing, one end of which is rotatably supported via a support pin on the control unit side and the other end of which is inside the casing. A projecting interlocking link, a swinging link having one end rotatably connected to the other end of the interlocking link, and the other end rotatably supported by a side surface portion of the valve plate via a detection pin, A variable displacement oblique shaft type hydraulic rotary machine characterized by comprising an output pin provided in the interlocking link in order to feed back the tilt amount of the valve plate to the control section in a proportionally reduced state. .