JPH0475426B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field The present invention relates to a timing adjustment device used, for example, in a hydraulic control device for an automatic transmission.

(B) Prior Art As a conventional timing adjustment device for an automatic transmission, there is, for example, one shown in FIG. 1 (such as the 3-2 timing valve disclosed in Japanese Patent Application Laid-open No. 55-47039).
The hydraulic switching valve 10 has a spool 14 that is pressed leftward in FIG. It is possible to switch between a position that prevents communication between the ports 18 and 20 (upper half position in the figure) and a position that allows communication between the ports 18 and 20 (lower half position in the figure). By controlling the hydraulic pressure of the port 16 of this hydraulic pressure switching valve 10, the hydraulic pressure 22 communicating with the port 18 is controlled.
and the oil passage 24 communicating with the port 20 can be communicated or disconnected. Oil passage 22 and oil passage 2
If you want to always communicate with 4 in only one direction,
In addition to the hydraulic switching valve 10, an oil passage 22 and an oil passage 24
It was necessary to provide a check valve 26 between the two. When the check valve 26 is provided in the direction shown in FIG. 1, for example, hydraulic pressure is supplied from the oil passage 22 to the oil passage 24, but no oil pressure can be supplied from the oil passage 24 to the oil passage 22.

However, in the conventional hydraulic control device, the hydraulic switching valve 10 and the check valve 26 were separately provided in this way, which increased the space required and the overall size of the hydraulic control device. BACKGROUND ART In automatic transmissions for vehicles in which a large number of various valves and the like must be arranged within a limited space, the increase in the size of the hydraulic control device is a major problem.

In addition, Japanese Patent Application Laid-open No. 53-68437 shows a device in which a check valve is placed inside the spool.
This is simply a check valve placed within the spool, and is not configured to bypass the orifice and adjust timing depending on the spool position.

(C) Purpose of the Invention The present invention achieves switching control of communication or disconnection between two oil passages and constant communication in one direction between the two oil passages using a single timing adjustment valve. The purpose is to make the device more compact.

(d) Structure of the Invention The timing adjustment device for an automatic transmission according to the present invention includes an oil passage 56 connected to an oil chamber of a friction engagement element;
A timing adjustment valve 14 that can bypass the orifice 66 provided in the pilot port 50d is provided, and the timing adjustment valve is controlled by the signal hydraulic pressure (governor pressure) acting on the pilot port 50d.
a first position in which the two ports 50b, 50c communicate with each other by a groove between the lands 52a, 52b;
0c and a second position covered by a land 52b, the two ports are connected to an upstream side 56 and a downstream side 58 of the orifice of the oil passage, respectively. A passage is provided inside the spool that communicates both ports when the spool is in the second position, and this passage allows oil to flow in one direction and prevents oil from flowing in the other direction. Check valves 62, 52d are provided. Note that reference numerals in parentheses indicate corresponding ones in the embodiments described later.

(e) Embodiments Examples of the present invention will be described below with reference to FIGS. 2 to 4 of the accompanying drawings.

FIG. 2 shows a schematic diagram of the power transmission mechanism of an automatic transmission with three forward speeds and one reverse speed. This power transmission mechanism includes an input shaft I to which rotational force from an engine output shaft E is transmitted via a torque converter T/C, an output shaft O to transmit driving force to a final drive device, a first planetary gear set G 1 , a first planetary gear set G 1 , and a first planetary gear set G ₁ . It has two planetary gear sets _G2 , a high and reverse clutch H&R/C, a forward clutch F/C, a band brake B, a low and reverse brake L&R/B, and a one-way clutch OWC. 1st planetary gear set G ₁
is sun gear S ₁ , internal gear R ₁ , and pinion gear P ₁ that meshes with both gears S ₁ and R ₁ at the same time.
It consists of a carrier PC that supports ₁ and
Further, the planetary gear set _G2 is composed of a sun gear _S2 , an internal gear _R2 , and a carrier _PC2 that supports a pinion gear _P2 that meshes with both gears _S2 and _R2 at the same time. Each component is connected as shown. The above power transmission mechanism includes a high and reverse clutch H&R/C, a forward clutch F/C, a band brake B, and a low and reverse brake L&R/B (one-way clutch).
By operating the OWC) in various combinations, each element of the planetary gear sets G ₁ and G ₂ (S ₁ , S ₂ ,
R ₁ , R ₂ , PC ₁ and PC ₂ ) can be changed, thereby varying the rotation speed of the output shaft O relative to the rotation speed of the input shaft I to obtain three forward speeds and one reverse speed. be able to.

FIG. 3 shows a hydraulic control device according to the present invention. This hydraulic control device includes a regulator valve 1, a manual valve 2, 1-2, a shift valve 3, 2-3
Shift valve 4, 3-2 downshift valve 5,
Line pressure booster valve 6, pressure modifier valve 7, throttle valve 8, throttle fuel safety valve 9, throttle modulator valve 10, 1st speed fixed range pressure reducing valve 1
1, an accumulator 12, a 3-2 timing valve 14, a high and reverse clutch pressure reducing valve 15, and a governor valve 16, which are connected to the torque converter T/C, high and reverse clutch H&R/C, and forward clutch F/C.
C, servo apply chamber S/A and servo release chamber S/ that activate or deactivate band brake B;
R, low and reverse brake L&R/B, and oil pump O/P as shown in the figure. With this configuration, the high and reverse clutch H&R/C, the forward clutch F/C, and the low and reverse brake L&R are activated depending on the vehicle speed and engine throttle opening.
Hydraulic pressure is distributed to the R/B, servo apply chamber S/A, and servo release chamber S/R as specified, except for the 3-2 timing valve 14, which is a timing adjustment device for an automatic transmission that is directly related to the present invention. The explanation of those will be omitted. The specific structural functions of the parts whose explanations are omitted are described in Japanese Patent Application No. 1982-26175 filed by the present applicant.

The following description will be made based on FIG. 4, which shows an enlarged view of the 3-2 timing valve 14, which is a timing adjustment device for an automatic transmission to which the present invention is applied. 3-2 The timing valve 14 includes a spool hole 50 having ports 50a to 50d, a spool 52 inserted into the spool hole 50, and a spring 54 that pushes the spool 52 downward in FIG.
It has The port 50a is a drain port, and the port 50b is an oil passage 5 to which hydraulic pressure is supplied when the 2-3 shift valve 4 is in the up position.
6, the port 50c is connected to an oil passage 58 communicating with the servo release chamber S/R, and the pilot port 50d is connected to an oil passage 60 which is a governor pressure circuit. Spool 52
has lands 52a and 52b, and a stepped hole 5 drilled from the bottom and end in FIG.
It has 2c. Inside the stepped hole 52c,
A seatable ball 62 is inserted into the stepped portion 52d of the stepped hole 52c. The ball 62 and the stepped portion 52d constitute a check valve.
The stepped hole 52c is closed by a press-fitted cap 64. The small diameter side of the stepped hole 52c is connected to lands 52a and 52b by the passage hole 52e.
It communicates with the annular groove between, and also has a stepped hole 5.
The large diameter side of 2c is connected to the land 5 by the passage hole 52f.
It communicates with the outer periphery of 2b. When the spool 52 is in the position shown in the left half of FIG. When in the position shown in , the passage hole 52f is arranged to communicate with the port 50c, and the passage hole 52e is arranged so as to communicate with the port 50b. Note that the oil passage 56 and the oil passage 58 communicate with each other via an orifice 66.

Next, the operation of this embodiment will be explained. When the vehicle speed is low and the governor pressure in the oil passage 60 is low,
The spool 52 is pushed by a spring 54 to the position shown in the left half of the figure. In this state, port 50b and port 50c are communicating, so
The oil passage 56 and the oil passage 58 are in a connected state. Therefore, when the 2-3 shift valve 4 is switched from the down position to the up position and oil pressure is supplied to the oil passage 56, this oil pressure is immediately supplied to the servo relay chamber S/R via the oil passage 58. Conversely, even when the 2-3 shift valve 4 is switched from the up position to the down position and the oil pressure in the oil passage 56 is drained, the oil pressure in the servo release chamber S/R is , and is immediately drained via the oil line 56. Therefore, when the vehicle speed is low, the band brake B can be engaged and released relatively quickly.

Conversely, when the vehicle speed is high and the governor pressure in the oil passage 60 is high, the spool 52 is in the position shown in the right half of FIG. 4. When the 2-3 shift valve 4 is switched from the down position to the up position, hydraulic pressure is supplied to the oil passage 56. The oil pressure in the oil passage 56 is applied to the port 50b.
and passes through the passage hole 52e of the spool 52 and acts on the ball 62 in the stepped hole 52c, pushing it away from the stepped part 52d, and connecting the passage hole 52e and the passage hole 5.
2f communicate with each other through the stepped hole 52c. Therefore, the oil passage 56 communicates with the oil passage 58 via the passage hole 52e, the stepped hole 52c, the passage hole 52f, and the port 50c. Therefore, in this case as well, hydraulic pressure is quickly supplied to the servo release chamber S/R. On the other hand, when the 2-3 shift valve 4 is switched from the up position to the down position and the oil passage 56 is drained. The hydraulic pressure in the servo release chamber S/R is about to be drained through the oil passage 58, but
The oil pressure of the oil passage 58 is connected to the port 50c and the passage hole 52f.
It acts on the ball 62 through the ball 62 to seat the ball 62 on the stepped portion 52d. Therefore, communication between the oil passage 58 and the oil passage 56 via the 3-2 timing valve 14 is blocked, and the hydraulic pressure in the oil passage 58 is discharged to the oil passage 56 only through the orifice 66. Therefore, in this case, the oil pressure in the servo release chamber S/R gradually decreases. That is, in places where the vehicle speed is high, the band brake B is slowly engaged. By this, 3-
The timing of the second shift can be adjusted, and the shift shock can be reduced. In the end, these 3
The -2 timing valve 14 can perform the same function as the combination of the conventional hydraulic switching valve 10 and check valve 26 shown in FIG.
Therefore, there is no need to provide a check valve in addition to the 3-2 timing valve 14, the required space is reduced, and the hydraulic control device can be downsized.

In addition, in this embodiment, the pilot port 50
Although the signal oil pressure acting on d is the governor pressure, other oil pressure, such as the throttle pressure, may be used.

(F) Effects of the Invention As explained above, according to the present invention, since the timing adjustment device for an automatic transmission is configured as described above, there is no need to provide a check valve in addition to the hydraulic switching valve. The required space can be reduced and the hydraulic control device can be downsized.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional hydraulic switching valve and check valve, FIG. 2 is a schematic diagram showing a power transmission section of an automatic transmission, and FIG. 3 is a hydraulic diagram showing a timing adjustment device for an automatic transmission according to the present invention. FIG. 4 is a diagram showing the entire control device, and FIG. 4 is a diagram showing a timing valve according to the present invention. 14...2-3 timing valve (timing adjustment valve), 50...spool hole, 50b, 5
0c...port, 50d...pilot port,
52... Spool, 52a, 52b... Land,
52c...Stepped hole, 52d...Stepped part, 52
e, 52f...passage hole, 54...spring, 5
6,58,60...Oil path, 62...Ball, 64
... Cap, 66 ... Orifice.

Claims (1)

[Claims] 1. A timing adjustment valve is provided that can bypass the orifice provided in the oil passage connected to the oil chamber of the friction engagement element, and the timing adjustment valve operates according to the signal hydraulic pressure acting on the pilot port. The spool has a spool that can be switched between a first position in which the two ports communicate with each other by a groove between the lands and a second position in which at least one of the two ports is covered by the land, The two ports are connected to the upstream and downstream sides of the orifice of the oil passage, respectively, and a passage is provided inside the spool that communicates the two ports when the spool is in the second position. A timing adjustment device for an automatic transmission characterized by being provided with a check valve that allows oil to flow in one direction and prevents oil from flowing in the other direction.