JP2002349699A - Gear speed changer for vehicle transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce space for a gear speed changer of the transmission which uses a motor. SOLUTION: The gear speed changer 4 is equipped with a shaft 11, a shift yoke 12, a gear selection mechanism 13, and a gear shift mechanism 14. The shift yoke 12 is mounted movably but not rotatably on the shaft 11. The gear shift mechanism 14 makes the shift yoke 12 rock. The gear select mechanism 13 makes the shift yoke 12 more in the longitudinal direction of the shaft 11 for the shift yoke 12 to select any one from among the spools 10, and comprises a male screw member 31, a motor 33 to turn the male screw member 31 and a female screw member 32. The male screw member 31 is arranged coaxially with the shaft 11 and rotatable relative to the latter. The female screw member 32 is arranged coaxially with the shaft 11, engages with the male screw member 31 and is coupled with the shift yoke 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear transmission for a vehicular transmission, and more particularly to an apparatus for operating a gear select mechanism by a motor.

[0002]

2. Description of the Related Art Manual transmissions are mainly used in large vehicles such as buses and trucks even today. In a manual transmission, a transmission lever and a transmission in a driver's seat are mechanically connected by a link mechanism such as a control rod.
Then, at the time of gear shifting, the driver operates the lever to physically drive the gear mechanism. For this reason, when the shift is frequently required, the lever operation requiring a certain amount of force places a heavy burden on the driver.

[0003] In order to solve this problem, a gear transmission operated by a motor is provided in a manual transmission.
A remotely operated manual transmission provided with a transmission ECU for controlling the gear transmission by an electric signal has been developed. In this transmission, the motor drives the gear mechanism, so that the gear can be shifted with a small force that merely operates the shift lever, and the burden on the driver regarding the shift lever operation is reduced.

Generally, in a manual transmission, a plurality of spools are provided side by side in a select direction. The gear transmission provided in the manual transmission connects and disconnects gears by driving the spool selected by the gear selection mechanism in the shift direction. The gear transmission usually includes a shift yoke having one end engageable with each spool, a shaft in which the shift yoke is splined in a non-rotatable manner, a gear select mechanism for moving the shift yoke on the shaft in a select direction, and a shift yoke. A gear shift mechanism that moves the spool in the shift direction is provided. For example, an electric ball screw mechanism is adopted as the gear select mechanism or the gear shift mechanism.

[0005]

In a conventional gear transmission using a motor, the rotation of the motor is converted into a linear motion by, for example, an electric ball screw mechanism. Then, the member that moves linearly is connected to the shift yoke by linkage, and the shift yoke on the shaft is moved in the select direction. Therefore, the electric ball screw mechanism is disposed parallel to the shaft, and the space occupied by the gear transmission is relatively large. Further, it is necessary to connect the movable part of the electric ball screw mechanism and the shift yoke with a linkage, and there is a high possibility that an eccentric load other than in the select direction acts on the shift yoke.

SUMMARY OF THE INVENTION It is an object of the present invention to reduce the space (compactness) of a gear transmission of a transmission using a motor and to suppress the eccentric load from acting on a shift yoke from a gear select mechanism. is there.

[0007]

According to a first aspect of the present invention, a gear transmission for a vehicle transmission comprises a shaft, a shift yoke, a gear select mechanism, and a gear shift mechanism. The shift yoke is mounted so as to be movable in the longitudinal direction of the shaft. Further, the shift yoke is non-rotatably mounted on the shaft. The gear shift mechanism is a mechanism that swings a shift yoke to apply a force to the spool from the shift yoke, and causes the shift gear to be connected or disconnected by movement of the spool. The gear select mechanism is a mechanism that moves the shift yoke in the longitudinal direction of the shaft and selectively makes the shift yoke correspond to an arbitrary spool. Further, the gear select mechanism includes a first screw member,
It has a motor and a second screw member. The first screw member is a member arranged coaxially with the shaft, and is rotatable with respect to the shaft. The motor rotates the first screw member. The second screw member is arranged coaxially with the shaft, meshes with the first screw member, and is connected to the shift yoke.

Here, when the first screw member is rotated by the motor, the second screw member meshing with the first screw member moves the shift yoke non-rotatably mounted on the shaft along the longitudinal direction of the shaft. Thereby, the gear selection mechanism moves the shift yoke to a position corresponding to an arbitrary spool. Here, the screw feed mechanism including the first screw member and the second screw member is arranged coaxially with the shaft. For example, by forming the screw member in a cylindrical shape, the screw member can be coaxially arranged on the outer peripheral side of the shaft. Since the screw feed mechanism is arranged coaxially with the shaft in this way, the weight and size of the apparatus can be reduced as compared with a conventional gear transmission in which a gear select mechanism is arranged parallel to the shaft.

Further, since the two screw members are arranged coaxially with the shaft, the shift yoke mounted on the shaft by the force acting on the shift yoke from the gear select mechanism causes eccentricity other than the force along the longitudinal direction of the shaft. The disadvantage that a load acts is suppressed. As a result, the movement of the shift yoke is further ensured, and the durability of the gear transmission is also improved.

According to a second aspect of the present invention, there is provided a gear transmission for a vehicle transmission according to the first aspect, wherein a groove is formed in the shaft at a position corresponding to each of the spools. The shift yoke includes a positioning mechanism. This positioning mechanism has an engaging member capable of engaging with the groove, and an elastic member for elastically supporting the engaging member. The second screw member is connected to the shift yoke via a gap.

Here, a groove is formed in the shaft, and a positioning mechanism for positioning the shift yoke by engaging an engaging member in the groove is provided. Even when a slight error occurs in the feed of the screw feed mechanism including the first screw member and the second screw member, the gap between the second screw member and the shift yoke absorbs the error, and the positioning is performed. Adverse effects on the positioning of the shift yoke by the mechanism are largely avoided. With such a relatively simple structure, in the device of the present invention,
This ensures that the shift yoke corresponds to any spool position.

According to a third aspect of the present invention, there is provided a gear transmission for a vehicle transmission according to the first aspect, further comprising a housing. The housing is immovable relative to the shaft in the longitudinal direction of the shaft. A groove is formed in the shift yoke at a position corresponding to each of the spools. The housing includes a positioning mechanism. This positioning mechanism has an engaging member capable of engaging with the groove, and an elastic member for elastically supporting the engaging member. The second screw member is connected to the shift yoke via a gap.

In this case, a positioning mechanism is provided in a housing that cannot move relative to the shaft, and a structure is employed in which an engaging member of the positioning mechanism is engaged with a groove of the shift yoke. Even when a slight error occurs in the feed of the screw feed mechanism including the first screw member and the second screw member, the gap between the second screw member and the shift yoke absorbs the error, and the positioning is performed. Adverse effects on the positioning of the shift yoke by the mechanism are largely avoided. Such a relatively simple structure ensures that the shift yoke corresponds to any spool position in the device of the present invention.

According to a fourth aspect of the present invention, there is provided a gear transmission for a vehicle transmission according to the second or third aspect, wherein the second screw member is shifted via a damper disposed in the gap. It is connected to the yoke.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] <Outline of Manual Transmission Automatic Transmission System> FIG. 1 shows a manual transmission automatic transmission system including a transmission (vehicle transmission) according to an embodiment of the present invention. .

In FIG. 1, a clutch 3 including a dry single-disc clutch disc is disposed between an engine 1 and a transmission 2. A gear transmission 4 is provided as an actuator for driving the transmission 2. As an actuator for driving the clutch 3, a clutch actuator 5 is provided.
The clutch actuator 5 has a master cylinder connected via a hydraulic circuit to a slave cylinder 6 provided near the clutch 3.

In this system, an engine ECU 51 and a transmission ECU 52 are provided and can communicate with each other. For example, they can exchange engine rotation information and accelerator opening information.

The engine ECU 51 controls the engine 1, and receives an accelerator opening signal from an accelerator pedal 54. The transmission ECU 52 mainly performs clutch control and shift control, and outputs a clutch control signal to the clutch actuator 5 and a shift control signal to the gear transmission 4. These control signals are signals for driving various motors.

The transmission ECU 52 receives signals from various sensors. In particular,
Idle signal from accelerator pedal 54, shift lever 5
5, a shift position signal, a clutch stroke signal from the clutch pedal 56, a clutch stroke signal and a hydraulic signal from the clutch actuator 5, a clutch 3
, A clutch rotation signal, a vehicle speed signal from the transmission 2, and a shift / select stroke signal from the gear transmission 4 are input to the transmission ECU 52.

In the system described above, the transmission ECU 52 automatically controls the clutch operation and the gear shifting operation. Further, a manual operation of performing a gear shift operation by operating the shift lever 55 can be selectively used.

The second master cylinder 57 linked to the clutch pedal 56 is connected to the slave cylinder 6 via an oil passage. Therefore, when the driver operates the clutch pedal 5
When the user operates the cylinder 6, the hydraulic pressure is supplied from the second master cylinder 57 to the slave cylinder 6, and the clutch connection / disconnection operation is performed. In this embodiment, the clutch pedal 56 is for emergency use only when a failure occurs in the electrical relationship of the clutch actuator 5 and the like, and is folded during normal running.

<Gear Transmission> The gear transmission 4 will be described in detail with reference to FIG. (Outline of Gear Transmission) The gear transmission 4 is a device that connects and disconnects the transmission gear of the transmission 2 based on a transmission control signal from the transmission ECU 52. As shown in FIG. 2, the spools 10 of the transmission 2 which are respectively held so as to move linearly by the shift rail 9 are arranged in the select direction (the left-right direction in FIG. 2). The gear transmission 4 selects one of these spools 10 and pushes it to
Is moved along the shift rail 9. Specifically, a claw 12b of the shift yoke 12 of the gear transmission 4 (described later)
Is the notch 1 of the spool yoke 10a of the spool 10.
0b, and the spool 1
0 moves. Then, due to the linear movement of the spool 10, the transmission gear is connected / disconnected via a synchronization mechanism including a not-shown cone clutch.

The gear transmission 4 mainly includes the shaft 1
1, a shift yoke 12, a gear select mechanism 13,
A gear shift mechanism 14 is provided. (Shaft) The vicinity of both ends of the shaft 11 is supported by the housing 45 via bearings. A spline 11 a is formed on the outer peripheral surface of the central portion of the shaft 11.

Further, the spline 11a of the shaft 11
Each of the grooves 11 is located at a position where a claw 12b of a shift yoke 12 described later enters a notch 10b of each spool 10.
b is provided.

(Shift Yoke) The shift yoke 12 has an inner peripheral spline 12 a
a. Therefore, the shift yoke 12
Although it is movable in the longitudinal direction of the shaft 11, its rotation is restricted with respect to the shaft 11. In addition, the shift yoke 12 swings the notch 10
b has a claw 12b that can be inserted.

Further, the shift yoke 12 is formed with a cylindrical hollow portion 12c perpendicular to the longitudinal direction of the shaft 11. The positioning mechanism 20 is disposed in the cylindrical hollow portion 12c. This positioning mechanism 20
Is a ball 21 that can be engaged with the groove 11b of the shaft 11.
And a lid 23 fixed to the shift yoke 12 and the ball 2
1 and a spring 22 for elastically connecting the lid 23. The positioning mechanism 20 holds the position of the shift yoke 12 in the select direction with a constant force by pressing the ball 21 against the groove 11 b by the urging force of the spring 22.

(Gear shift mechanism) Gear shift mechanism 14
Is obtained by swinging the shaft 11 so that the shift yoke 12
This mechanism applies a force to the spool 10 to move the spool 10 to connect and disconnect the speed change gear. Although the planetary gear reduction mechanism is used here as the gear shift mechanism 14, another mechanism such as a harmonic drive reduction mechanism or a cyclo (registered trademark) reduction mechanism may be used.

(Structure of Gear Select Mechanism) The gear select mechanism 13 moves the shift yoke 12 in the longitudinal direction of the shaft 11 (selection direction Ds).
Is a mechanism for selectively corresponding to any spool 10. The gear selection mechanism 13 mainly includes a male screw member 31, a female screw member 32, and an electric motor 33.

The cylindrical portion of the male screw member 31 is disposed on the outer peripheral side of the end of the shaft 11 via the radial bearings 35 and 36. On the outer peripheral surface of the cylindrical portion of the male screw member 31, a male screw 31b is formed. A rotating shaft 33 of the electric motor 33 is provided at an end 31 a of the female screw member 31.
a are connected. Therefore, the male screw member 31 also rotates by the rotation of the electric motor 33.

The female screw member 32 is a cylindrical member, and a female screw 32a formed on the inner peripheral surface at one end is formed with a male screw member 31.
With the male screw 31b. The female screw member 3
A spline 32 b having the same shape as the spline 12 a of the shift yoke 12 is formed in the inner peripheral portion at the other end of the second 2, and is engaged with the spline 11 a of the shaft 11.
Further, a flange 32c is formed on the outer periphery of the other end of the female screw member 32. And this flange 32c
The retaining ring 61 is attached at a constant interval in the select direction from the retaining ring 61.

In the inner peripheral portion at the end of the shift yoke 12, the retaining ring 62 is separated from the contact portion 12d in the select direction by the same distance as the distance between the flange 32c and the retaining ring 61. Is attached. The annular space surrounded by the flange 32c of the female screw member 32, the contact portion 12d of the shift yoke 12, and the retaining rings 61 and 62 has two washers with two opposed dish plates 63 interposed therebetween. 64 are arranged and play the role of a damper. The damper and the female screw member 32 and the shift yoke 1
2 (see FIG. 2), the female screw member 32 and the shift yoke 12 move in the select direction by the compressible amount t of the two dish plates 63 equal to the dimension t of the gap S. They are relatively movable and connected to each other.

Further, the gear select mechanism 13 is provided with a sensor (not shown) capable of detecting the amount of movement of the shift yoke 12 along the select direction. (Operation of Gear Select Mechanism) Transmission ECU
When the electric motor 33 is rotated by the gear select signal from the motor 52, the male screw member 31 connected to the rotation shaft 33 a of the electric motor 33 rotates around the shaft 11 via the radial bearing 37 fixed to the housing 45. I do. At this time, since the female screw member 32 meshing with the male screw member 31 is connected to the shaft 11 via spline engagement, the rotation is restricted, and therefore, the female screw member 32 is in the axial direction of the shaft 11 (selection direction). Moving. And
When the female screw member 32 compresses the dish plate 63 with a force exceeding the holding force of the shift yoke 12 by the positioning mechanism 20, the shift yoke 12 moves on the shaft 11 in the axial direction (selection direction).

Further, even if the electric current of the electric motor 33 is interrupted by a sensor for detecting the amount of movement of the shift yoke 12,
The electric motor 33 does not stop immediately due to the effect of inertia, and the female screw member 32 further moves and stops. This movement time is required to be short (about 0.1 second), but it is generally difficult to control the exact stop position of the female screw member 32. However, in the gear transmission 4 of the present embodiment, the groove 1 is formed in the spline 11a of the shaft 11.
1b, the shift yoke 12 is moved by the positioning mechanism 20 including the ball 21 and the spring 22.
It will be forcibly fixed at the exact stop position. However, the stop position of the female screw member 32 and the shift yoke 1
2 is different from the accurate stop position by the compressible amount t of the two dish plates 63 (the dimension t of the gap S in FIG. 2).
Must be within.

(Characteristics of Gear Transmission) In this device, a screw feed mechanism including a male screw member 31 and a female screw member 32 meshing with each other is arranged coaxially with the shaft 11.
Since the screw feed mechanism is arranged coaxially with the shaft 11 as described above, the weight and size of the apparatus can be reduced as compared with a conventional gear transmission in which a gear select mechanism such as an electric ball screw is arranged parallel to the shaft 11. I can plan.

The two screw members 31, 32 are connected to the shaft 1
1, an eccentric load other than a force along the longitudinal direction of the shaft 11 acts on the shift yoke 12 mounted on the shaft 11 by the force acting on the shift yoke 12 from the gear select mechanism 13. The problem of being lost is suppressed. That is, as shown in FIG. 2, since the structure is such that the force from the female screw member 32 acts on the vicinity of the center circumference of the shift yoke 12, both the screw members 3
The forces acting on the gears 1, 32 and the shift yoke 12 are substantially only tensile and compressive loads, so that the operation of the gear transmission 4 is ensured and the durability is improved.

[Second Embodiment] In the first embodiment, the female screw member 32 and the shift yoke 12 are connected via the dish plate 63 and the washer 64. However, without using such a damper structure, It is also possible to adopt a structure in which the female screw member 32 and the shift yoke 12 are connected with only a predetermined gap opened (see FIG. 3).

Here, on the outer peripheral portion at the other end of the female screw member 32, not the flange 32c but two convex portions 32d are formed. The projection 32d is provided with the shift yoke 1
2 is disposed in the concave portion 12e formed in the second concave portion. Recess 12
e is formed with a notch through which the projection 32d passes through the wall 65 forming the e.
After being inserted into the concave portion 12e through the notch, it is connected to the shift yoke 12 by rotating it by a predetermined amount. The width of the concave portion 12e in the select direction is larger than the width of the convex portion 32d in the select direction. Therefore, in this state, the female screw member 32 is connected to the shift yoke 12 with a predetermined gap.

When the electric motor 33 is rotated by a gear select signal from the transmission ECU 52, the male screw member 31 connected to the rotating shaft 33a of the electric motor 33 is connected to the radial bearing 37 fixed to the housing 45.
And rotates around the shaft 11. At this time, since the female screw member 32 meshing with the male screw member 31 is connected to the shaft 11 via spline engagement, the rotation is restricted, and therefore, the female screw member 32 is in the axial direction of the shaft 11 (selection direction). Moving. And the female screw member 32
The shift yoke 12 moves on the shaft 11 in the axial direction (selection direction) after the protrusion 32d moves in the gap and comes into contact with the shift yoke 12.

Further, even if the electric current of the electric motor 33 is interrupted by a sensor for detecting the amount of movement of the shift yoke 12,
The electric motor 33 does not stop immediately due to the effect of inertia, and the female screw member 32 further moves and stops. This movement time is required to be short (about 0.1 second), but it is generally difficult to control the exact stop position of the female screw member 32. However, in the gear transmission 4 of the present embodiment, the groove 1 is formed in the spline 11a of the shaft 11.
1b, the shift yoke 12 is moved by the positioning mechanism 20 including the ball 21 and the spring 22.
It will be forcibly fixed at the exact stop position. However, the stop position of the female screw member 32 and the shift yoke 1
2 must be smaller than the difference between the width of the concave portion 12e in the select direction and the width of the convex portion 32d in the select direction.

[Third Embodiment] In the first embodiment, the shift yoke 12 is stopped at a precise stop position by adopting a structure in which the groove 11b is formed in the shaft 11 and the positioning mechanism 20 is provided in the shift yoke 12. Figure 4
When the structure shown in FIG.
Can be stopped at an accurate stop position.

Here, instead of providing a groove in the shaft 11, a groove 12f is provided in a part of the outer peripheral surface of the shift yoke 12. These grooves 12f are provided at positions where the claws 12b of the shift yoke 12 enter the notches of the respective spools 10. Then, the positioning mechanism 120 is fixed to the housing 45. Specifically, a cylindrical holding portion is formed in a portion of the housing 45 located on the outer peripheral side of the groove 12f, and the positioning mechanism 1 is formed in the cylindrical cavity 45a of the holding portion.
20 are arranged. The positioning mechanism 120 includes a ball 121 capable of engaging with the groove 12 f of the shift yoke 12, a lid 123 fixed to the housing 45, the ball 121 and the lid 1.
23 and a spring 122 for elastically connecting the spring 23 with the spring 122. The positioning mechanism 120 holds the position of the shift yoke 12 in the select direction with a constant force by pressing the ball 121 against the groove 12f by the urging force of the spring 122.

[0042]

According to the present invention, since the screw feed mechanism including the first screw member and the second screw member is arranged coaxially with the shaft, the conventional gear in which the gear select mechanism is arranged parallel to the shaft. The device can be made lighter and more compact than a transmission.

Also, since both screw members are arranged coaxially with the shaft, the shift yoke mounted on the shaft by the force acting on the shift yoke from the gear select mechanism causes eccentricity other than the force along the longitudinal direction of the shaft. The disadvantage that a load acts is suppressed. As a result, the movement of the shift yoke becomes more reliable, and the durability of the gear transmission is also improved.

[Brief description of the drawings]

FIG. 1 is a diagram of a manual transmission automatic transmission system including a transmission (vehicle transmission) according to an embodiment of the present invention.

FIG. 2 is a sectional view of the gear transmission according to the first embodiment;

FIG. 3 is a sectional view of a gear transmission according to a second embodiment.

FIG. 4 is a sectional view of a gear transmission according to a third embodiment.

[Explanation of symbols]

 2 Transmission 10 Spool 11 Shaft 11b Groove 12 Shift yoke 13 Gear select mechanism 14 Gear shift mechanism 20, 120 Positioning mechanism 21, 121 Ball (engaging member) 22, 122 Spring (elastic member) 31 Male screw member (first screw member) 32 female screw member (second screw member) 33 electric motor 45 housing 63 dish plate (damper) 64 washer (damper) S gap

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Toru Kagei 1-1-1 Kida Motomiya, Neyagawa-shi, Osaka F-term in EXEDY Corporation (reference) 3J067 AA01 AB23 AB24 AC03 BA58 DA41 DB32 FA26 FB83 FB85 GA01

Claims (4)

[Claims] A shaft; a shift yoke mounted on the shaft so as to be movable in a longitudinal direction of the shaft and not to rotate relative to the shaft; and moving the shift yoke in a longitudinal direction of the shaft. A gear selecting mechanism for selectively making the shift yoke correspond to an arbitrary spool; and a force acting on the spool from the shift yoke by swinging the shift yoke, and the movement of the spool causes a shift gear to be disconnected. A gear shift mechanism for making contact with the shaft, wherein the gear selection mechanism is arranged coaxially with the shaft and is rotatable relative to the shaft; a first screw member; a motor for rotating the first screw member; And a second screw member which is coaxially arranged and meshes with the first screw member and is connected to the shift yoke. Gear transmission for a vehicle transmission. 2. A groove is formed in the shaft at a position corresponding to each of the spools. The shift yoke resiliently engages an engaging member capable of engaging with the groove and the engaging member. The gear transmission according to claim 1, further comprising a positioning mechanism having an elastic member for supporting, wherein the second screw member is connected to the shift yoke via a gap. 3. A shift housing further comprising: a housing that cannot move relative to the shaft along a longitudinal direction of the shaft, wherein the shift yoke has a groove formed at a position corresponding to each of the spools. The housing includes a positioning mechanism having an engaging member capable of engaging with the groove and an elastic member for elastically supporting the engaging member. The second screw member includes a gap with the shift yoke via a gap. The gear transmission of a vehicle transmission according to claim 1, wherein the gear transmission is connected. 4. The gear transmission according to claim 2, wherein the second screw member is connected to the shift yoke via a damper disposed in the gap.