JPH04321868A - Rotary valve for automatic transmission - Google Patents

Abstract

PURPOSE:To reduce friction force between a spool and a valve housing and ensure seal property in a rotary valve for automatic transmission which accommodates the free-rotating spool in the inside of the valve housing. CONSTITUTION:An oil passage 120 is provided at the center in axial direction of a spool 7 which is accommodated in the inside of a valve housing 1 and is rotated and driven by a pulse motor 6. Oil passages 121 to 125 which pass through the spool 7 in the direction of diameter are connected to the oil passage 120. Oil pressure from an input port 13 which is connected to an oil pressure source is supplied to the oil passage 120 via a feed pipe 14. Load which acts in axial direction due to oil pressure is received at a short section of the spool 7 by a thrust bearing 10. Side force does not act due to oil supply from axial direction of the spool 7, friction force is reduced, and seal property between the valve housing 1 and the spool 7 is improved.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention rotates a spool rotatably housed inside a valve housing with an actuator, and selectively applies hydraulic pressure from a hydraulic source to a plurality of frictional engagement elements via the spool. Regarding rotary valves for automatic transmissions.

0002

2. Description of the Related Art Conventionally, such rotary valves for automatic transmissions are disclosed in, for example, Japanese Patent Application Laid-Open No. 63-312577, Japanese Patent Application Laid-Open No. 61-41056, or Japanese Patent Application Laid-open No. 61-2.
The one described in Japanese Patent No. 18849 is known.

0003

However, in the conventional rotary valve for an automatic transmission described above, line pressure supplied from a hydraulic source through an input port formed in the valve housing acts radially on the outer peripheral surface of the spool. Therefore, there was a problem in that the outer circumferential surface on the opposite side of the spool was pressed against the inner circumferential surface of the valve hole of the valve housing, preventing smooth rotation.

[0004] In order to avoid such inconveniences, it is conceivable to form a circumferential groove on the outer peripheral surface of the spool through which line pressure is transmitted to cancel out the side force. However, forming such a circumferential groove not only increases the processing cost of the spool, but also creates the problem of sealing between the oil passage opening on the outer circumferential surface of the spool and the circumferential groove. It is necessary to extend the seal length to ensure a sufficient seal length, or to reduce the gap between the spool and the valve housing to prevent oil leakage. However, when doing the above, new problems arise, such as the total length of the spool increasing, making the rotary valve as a whole larger, and the frictional force between the spool and the valve housing increasing, making the driving pulse motor larger. Resulting in.

The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a rotary valve for an automatic transmission that allows smooth rotation of the spool and easily ensures sealing performance.

[0006]

[Means for Solving the Problems] In order to achieve the above object, the present invention rotates a spool rotatably housed inside a valve housing with an actuator, and applies hydraulic pressure from a hydraulic source through the spool. In a rotary valve for an automatic transmission that selectively supplies a plurality of friction engagement elements, the spool has a central oil passage extending along its rotation axis and a radial oil passage extending radially symmetrically from the central oil passage. The first feature is that the central oil passage has an oil supply port opened at an axial end portion of the central oil passage.

[0007] In addition to the above-mentioned first feature, the present invention also has the following features:
A second feature is that a thrust bearing is provided between the spool and the valve housing to receive a load acting in the axial direction of the spool.

[0008] In addition to the above-mentioned first feature, the present invention also has the following features:
A third feature is that a feed pipe connected to a hydraulic power source is inserted into the central oil passage.

[0009] In addition to the above-mentioned third feature, the present invention also has the following features:
A fourth feature is that a bush is installed between the outer periphery of the feed pipe and the inner periphery of the oil path of the spool.

0010

Embodiments Hereinafter, embodiments of the present invention will be explained with reference to the drawings.

1 to 7 show a first embodiment of the present invention, in which FIG. 1 is a longitudinal sectional view of the rotary valve, FIG. 2 is a sectional view taken along the line 2-2 in FIG. 1, and FIG. 3-3 line sectional view of
4 is an explanatory diagram of the action corresponding to FIG. 3, FIG. 5 is a perspective view of the spool, FIG. 6 is a developed view of the outer peripheral surface of the spool, and FIG. 7 is a diagram of FIG.
7(a)-7(a) line to 7(e)-7(e) line sectional view of FIG.

In FIG. 1, reference numeral V denotes a rotary valve for an automatic transmission, which selects hydraulic pressure from a hydraulic source for its plurality of frictional engagement elements in order to establish a desired gear stage in the automatic transmission of an automobile. It functions to supply

The rotary valve V includes a valve housing 1 having a valve hole 11 with a circular cross section in the center, a cover plate 3 fixed with a plurality of bolts 2 so as to close an opening on the left end side of the valve housing 1, and a valve housing 1. A pulse motor 6 as an actuator is fixed to the right end side of the housing 1 with a plurality of bolts 5 passing through the mounting flange 4, and the pulse motor 6 is rotatably housed in the valve hole 11 of the valve housing 1 and is rotationally driven by the pulse motor 6. The spool 7 has a generally cylindrical shape.

As is clear from FIG. 2,
A chamfered D-shaped connecting member 9 is provided at the tip of the output shaft 8 of the pulse motor 6 that extends inside the valve housing 1.
are spline-coupled, and this connecting member 9 engages with a D-shaped recess 71 formed in the right end face of the spool 7. Therefore, by driving the pulse motor 6, the spool 7 can be rotated within the valve hole 11 of the valve housing 1 by a predetermined angle. A thrust bearing 10 is installed between the right end surface of the spool 6 and the inner wall surface of the valve housing 1, and the thrust bearing 10 pushes the spool 7 to the right while allowing the spool 7 to rotate freely. The load is received.

As is clear from FIGS. 1 and 3, a small diameter portion 72 defining an annular space 11 between the spool 7 and the valve hole 11 is formed at the left end of the spool 7. An oil passage 120 bored along the rotation axis of the spool 7 opens at the left end face. A recess 31 is formed in the cover plate 3 so as to face the left end surface of the spool 7, and an input port 13 connected to a hydraulic power source (not shown) is bored in this recess 31. The input port 13 and the oil passage 120 of the spool 7 are connected to the feed pipe 14
connected via. That is, the flange 141 formed at the left end of the feed pipe 14 fits into the recess 31 and is pressed and fixed by the annular retainer 15 and clip 16. At this time, a pair of seal members 17 and 18 are installed between the recess 31 and the retainer 15. On the other hand, the right end of the feed pipe 14 is inserted into the oil passage 120 of the spool 7 via the bush 19. Thereby, the line pressure supplied from the hydraulic source to the input port 13 is transferred to the oil path 120 of the spool 7 via the feed pipe 14.
is supplied to

As is clear from FIG. 5,
The small diameter portion 72 of the spool 7 has a pin 2 extending in the radial direction.
0 is implanted, and a bolt 21 whose tip reaches the inside of the annular space 11 is screwed into the valve housing 1. An annular space 11 is provided between the pin 20 and the bolt 21.
Engagement portions 2 formed at both ends of the coil spring 22 housed in the
21 and 222 are respectively locked. coil spring 2
2 applies a set load in advance so as to bias the spool 7 in the rotational direction (direction of arrow A in FIGS. 3 and 5) and also in the axial direction (direction of arrow B in FIGS. 1 and 5). It is installed in a closed state. Small diameter part 7 of spool 7
A pair of step portions 73 and 74 are formed at the right end of 2.
One of the stepped portions 73 is such that the spool 7 is connected to the coil spring 2.
When the spool 7 rotates with the elastic force of 2, it engages with the bolt 21 and restricts the rotation end of the spool 7.

As is clear from FIGS. 1, 5, and 6, the oil passage 120 extends through the spool 7 in the diametrical direction.
Five parallel oil passages 121 to 125 communicating with each other are bored. In addition, the five oil passages 1 are provided on the outer circumference of the spool 7.
Two drain grooves 231 to 235 are cut in the circumferential direction so as to be located on both sides of drain grooves 21 to 125.

As is clear from FIGS. 1, 3, and 7, the valve housing 1 has five oil passages 1 for the spool 7.
21 to 125, five oil passages 24 that can communicate with each other.
1 to 245 are drilled in the radial direction. Each oil passage 241
.about.245 are formed radially with a phase difference of a predetermined angle, and the opening at the outer end is closed by the plug 25. Each of the oil passages 241 to 245 is an output port 271 that opens to the cover plate 3 via oil passages 261 to 265 axially bored in the valve housing 1.
~275, and those output ports 271 ~27
5 are respectively connected to frictional engagement elements for establishing the first to fifth gear stages. Also, in the valve housing 1,
Five pairs of drain grooves 231 to 235 formed in the spool 7
5 pairs of drain ports 281 to 285 that can communicate with
is formed.

Next, the operation of the first embodiment of the present invention having the above configuration will be explained.

The spool 7 is, for example, as shown in FIGS. 1 and 7(c).
Input port 13 from the hydraulic source when in the third gear position shown in
The line pressure supplied to the valve housing 1 reaches an oil passage 120 formed in the axial direction of the spool 7 via the feed pipe 14, an oil passage 123 extending radially from the oil passage 120, and an oil passage 123 extending radially through the valve housing 1. passage 243 , and an oil passage 263 extending axially through the valve housing 1
The signal is transmitted to the output port 273 via the output port 273. As a result, the frictional engagement element of the automatic transmission connected to the output port 273 is activated, and the third gear is established. At that time, the other four output ports 271, 272, 274
, 275 is the oil passage 2 formed in the valve housing 1.
61 ,262 ,264 ,265 ;241 ,2
42 , 244 , 245 , and a drain port 281 formed in the valve housing 1 via the drain grooves 231 , 232 , 234 , 235 formed in the spool 7
, 282 , 284 , 285 . That is, when the spool 7 is in the third speed position, the input port 13 is connected only to a specific output port 273 among the five output ports 271 to 275.

When the spool 7 is rotated to the first speed position shown in FIG. 7(a) by driving the pulse motor 6, the input port 13 is connected to the oil passages 120, 1
21 and oil passages 241 and 26 of the valve housing 1
1 to the output port 271 to establish the first gear in the automatic transmission. At this time, the other four output ports 272 to 275 are connected to the drain port 282.
~285 is connected. Similarly, the pulse motor 6
When the spool is rotated to the positions shown in FIGS. 7(b), (d), and (e), the 2nd, 4th, and 5th gear positions are established, respectively.

When the rotary valve V is operating as described above, the line pressure from the hydraulic source is input to the input port 13.
The spool 7 is supplied to the oil passage 120 formed in the axial direction of the spool 7 through the feed pipe 14.
is pressed rightward by the line pressure. At this time, radial oil passages 121 communicating with the central oil passage 120
~125 are formed axially symmetrically so as to pass through the spool 7 in the diametrical direction, so the side force acting on the spool 7 is canceled out. As a result, spool 7
This prevents a large frictional force from being pressed in the radial direction and exerting a large frictional force between the valve hole 11 of the valve housing 1 and the valve hole 11 of the valve housing 1. The spool 7 is also pushed to the right by the coil spring 22, but the axial rightward load is received by the thrust bearing 10 provided at the right end of the spool 7, so the spool 7 moves smoothly with a small driving force. Can be rotated. Moreover, since the spool 7 biased rightward is positioned in the axial direction by the thrust bearing 10, the oil passages 121 to 125 of the spool 7
and the oil passages 241 to 245 of the valve housing 1 are automatically aligned. Further, the line pressure supplied from the feed pipe 14 to the spool 7 is sealed by a bush 19 installed between the feed pipe 14 and the oil passage 120, and is opened at the inlet end of the oil passage 120 and the outer peripheral surface of the spool 7. Since the oil passages 121 to 125 are sufficiently far apart, the oil passage 120 and the other oil passages 121
~125 can be prevented from shorting.

Now, in the unlikely event that the pulse motor 6 breaks down and cannot drive the spool 7, the spool 7 is rotated by the elastic force of the coil spring 22 installed between the valve housing 1 and the spool 7. Stepped portion 7 formed in 7
3 is in contact with the bolt 21 as shown in FIG. 4, that is, the fifth speed position, which is the highest speed of the automatic transmission. In addition, even if the spool 7 does not rotate smoothly due to step-out of the pulse motor 6 or dust clogging, the spool 7 can be automatically rotated by detecting the abnormality using an appropriate sensor and cutting off the power to the pulse motor 6. can be rotated to the 5th gear position.

The target position for rotating the spool 7 by the coil spring 22 is not limited to the 5th speed position, but may be any high speed position such as the 4th speed position. Further, if the rotary valve V has a neutral position, the spool 7 may be rotated toward the neutral position.

Next, a second embodiment of the present invention will be explained based on FIGS. 8 to 11.

In this embodiment, the coil spring 22 has no set load in the axial direction, but only a set load in the rotational direction. A ball support member 29 is provided on the left end surface of the spool 7, and a ball 31 biased leftward by a spring 30 is slidably supported inside the ball support member 29. On the other hand, the retainer 15 attached to the cover plate 3 has five recesses 151 to 155 formed on its circumference in which the balls 31 can engage, and the balls 3 are biased by a spring 30.
1 and the recesses 151 to 155 of the retainer 15 constitute a click stop mechanism.

According to this embodiment, the spool 7
When the spool 7 stops at any one of the first to fifth speed positions, the balls 31 are engaged with the corresponding recesses 151 to 155 to precisely position the spool 7. Moreover, since the spool 7 is urged to the right by the reaction of the elastic force of the spring 30 that presses the ball 31, the spool 7 is pressed against the thrust bearing 10 by the load in the right direction due to line pressure, and its axis Directional positioning can be performed. Note that the ball 31 is attached to the valve housing 1.
Similar effects can be obtained by supporting the ball 31 on the side and engaging the ball 31 in a recess provided on the spool 7 side.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various small design changes can be made without departing from the scope of the present invention as set forth in the claims. It is possible to do this.

[0029]

As described above, according to the first feature of the present invention, a central oil passage extending along the rotation axis of the spool and a radial oil passage extending radially symmetrically from the central oil passage are formed in the spool. In addition, since the oil supply port is opened at the axial end of the central oil passage, side force is prevented from acting on the spool, and as a result, the frictional force between the spool and the valve housing is reduced, and a small driving force is required. It becomes possible to drive the spool reliably. Furthermore, since a sufficient distance is secured between the axial end of the spool to which hydraulic pressure is supplied and the outer peripheral surface of the spool, leakage of hydraulic pressure can be prevented without particularly increasing the sealing performance between the spool and the valve housing.

According to the second feature of the present invention, a thrust bearing is provided between the spool and the valve housing to receive the load acting in the axial direction of the spool, so that the spool is not affected by the axial load. can be rotated smoothly. Moreover, since the spool pressed in the axial direction is positioned by the thrust bearing, the axial positional relationship between the spool and the valve housing can always be maintained constant.

According to the third feature of the present invention, since the feed pipe connected to the hydraulic power source is inserted into the central oil passage,
It becomes possible to reliably supply hydraulic pressure from a hydraulic source to a spool with a simple structure.

According to the fourth feature of the present invention, since the bush is installed between the outer circumference of the feed pipe and the inner circumference of the oil passage of the spool, leakage of hydraulic pressure can be prevented without interfering with the rotation of the spool. can.

[Brief explanation of drawings]

[Fig. 1] Longitudinal cross-sectional view of a rotary valve according to the first embodiment

[Figure 2] Cross-sectional view taken along line 2-2 in Figure 1

[Figure 3] Cross-sectional view taken along line 3-3 in Figure 1

[Fig. 4] Explanatory diagram of the action corresponding to Fig. 3

[Figure 5] Perspective view of spool

[Figure 6] Developed view of the outer peripheral surface of the spool

[Fig. 7] Lines 7(a)-7(a) to 7(e)-7(
e) Line sectional view

[Fig. 8] Longitudinal cross-sectional view of the rotary valve according to the second embodiment

[Figure 9] Cross-sectional view taken along line 9-9 in Figure 8

[Figure 10] Cross-sectional view taken along line 10-10 in Figure 8

[Figure 11] Enlarged view of part 11 in Figure 8

[Explanation of symbols]

1... Valve housing 6... Pulse motor (actuator) 7...
... Spool 10 ... Thrust bearing 120 ... Oil path (central oil path) 121 to 125 ... Oil path (radial oil path) 14 ...
Feed pipe 19...Bush

Claims (4)

[Claims] [Claim 1] A spool (7) rotatably housed inside a valve housing (1) is connected to an actuator (6).
The spool (7) is rotated by the hydraulic pressure from the hydraulic source.
In the rotary valve for an automatic transmission that selectively supplies a plurality of frictional engagement elements via the spool (7),
A central oil passage (120) extending along the rotation axis and radial oil passages (121 to 125) extending radially and axially symmetrically from the central oil passage (120) are formed, and the central oil passage (120) A rotary valve for automatic transmissions, characterized by having a fuel filler opening at the axial end. 2. A thrust bearing (10) is provided between the spool (7) and the valve housing (1) to receive a load acting in the axial direction of the spool (7). The rotary valve for automatic transmission according to item 1. 3. The rotary valve for an automatic transmission according to claim 1, wherein a feed pipe (14) connected to a hydraulic power source is inserted into the central oil passage (120). 4. The automatic transmission according to claim 3, wherein a bush (19) is installed between the outer circumference of the feed pipe (14) and the inner circumference of the oil passage (120) of the spool (7). rotary valve.