JP3516767B2 - Hydraulic control device for automatic transmission - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control device for an automatic transmission.

[0002]

2. Description of the Related Art As a conventional hydraulic control device for an automatic transmission, there is one disclosed in JP-A-1-210648. The hydraulic control device for an automatic transmission shown in this figure includes a hydraulic control valve (lock-up relay valve), a reverse stage prohibition valve, and a signal hydraulic control valve that supplies and discharges signal hydraulic pressure to these.
(Solenoid valve). The hydraulic control valve is provided on the side opposite to the second signal oil chamber where the signal hydraulic pressure from the signal hydraulic control valve is supplied and discharged, and on the side opposite to the second signal oil chamber, except when shifting to the reverse gear (2 The first signal oil chamber to which the clutch engagement pressure is supplied, and the supply to the apply port or release port and the torque converter depending on the signal oil pressure and the clutch engagement pressure. It is possible to switch between communication and cutoff with the hydraulic pressure inlet port to which the hydraulic pressure is constantly supplied. The reverse speed prohibiting valve can switch between a side that permits the establishment of the reverse speed and a side that prohibits the reverse speed by supplying and discharging the signal hydraulic pressure from the signal hydraulic pressure control valve.

When the signal oil pressure is supplied from the signal oil pressure control valve to the second signal oil chamber of the oil pressure control valve and the reverse stage prohibition valve, the oil pressure control valve shuts off the Apply port and the oil pressure inlet port (that is, The release port and the hydraulic pressure inlet port are connected to each other), and the reverse gear prohibition valve is changed to a side that permits the establishment of the reverse gear. On the other hand, when the signal oil pressure from the signal oil pressure control valve is discharged from the second signal oil chamber and the reverse stage prohibition valve of the oil pressure control valve, the oil pressure control valve supplies the clutch engagement pressure to the first signal oil chamber. Only when the reverse speed is established, the switching control of the automatic transmission that communicates the apply port with the hydraulic pressure inlet port is performed, and the reverse speed prohibition valve is switched to the side that prohibits the establishment of the reverse speed. In this manner, the single signal hydraulic control valve controls the hydraulic control valve that operates only on the forward side and the reverse stage prohibition valve.

[0004]

However, in the above-described conventional hydraulic control system for an automatic transmission, when the reverse gear prohibiting valve is switched to the side that prohibits the establishment of the reverse gear,
In order to prevent the hydraulic control valve from performing the switching control of the automatic transmission that connects the apply port and the hydraulic inlet port, the clutch engagement pressure is supplied at a time other than when shifting to the reverse gear. It is necessary to provide an oil chamber. For this reason,
Although the hydraulic control valve and the reverse-travel prohibition valve are controlled by a single signal hydraulic control valve to reduce the size and cost of the hydraulic control device, the first signal is transmitted to the hydraulic control valve. An oil chamber must be provided. This allows
Since the hydraulic control valve becomes large and the price becomes high, there is a problem that the hydraulic control device cannot be downsized as expected and the price cannot be reduced. The present invention is intended to solve such a problem.

[0005]

SUMMARY OF THE INVENTION The present invention is directed to a first oil passage (1) in which hydraulic pressure is not supplied when a reverse range is selected.
8) A control valve (2) that can switch between a communication side that communicates the second oil passage (19) with the communication side and a cutoff side that blocks this communication.
0) and the reverse range pressure generated when the reverse range is selected to the friction element (32) between the supply side for supplying and the cutoff side for interrupting the reverse range inhibition valve (36). , 60) and a signal hydraulic pressure control valve (22) capable of supplying and shutting off signal hydraulic pressure for activating the switching of the control valve (20) and the reverse stage inhibition valve (36, 60). In a hydraulic control device for a transmission, the first oil passage (18) and the second oil passage (19)
Is an oil passage capable of bypassing the orifice (16) provided in the oil passage (12) for supplying hydraulic pressure to the clutch (10).

Further, in the hydraulic control device for an automatic transmission according to the present invention as defined in claim 2, the reverse range prohibit valve (36) is provided with a reverse range in which the reverse range pressure is supplied to the friction element (32). The pressure oil passage (42) and the forward low speed range pressure oil passage (44) to which the forward low speed range pressure generated when the forward low speed range is selected can be switched so as to communicate with each other. Yes, the reverse stage prohibition valve (36) causes the friction element (32) to set the reverse range pressure oil to the friction element (32) when the signal hydraulic pressure from the signal hydraulic pressure control valve (22) is supplied or cut off. The signal hydraulic pressure control valve (22) is switched while the path (42) is switched to the communicating side.
In the other of the cases where the signal hydraulic pressure from is supplied and cut off, it is configured to switch to the side in which the forward low speed range pressure oil passage (44) communicates with the friction element (32). Characterize.

Further, in the hydraulic control system for an automatic transmission according to the present invention as defined in claim 3, the reverse stage prohibiting valve is provided with a port communicating with the forward low speed range first speed oil passage (44). The reverse stage prohibiting valve (6
0), a shuttle valve (62) is provided between the reverse stage prohibition valve (60) and the friction element (32), and an output oil passage (64) of the reverse stage prohibition valve (60) is connected to the shuttle valve (64). 6
2) Communicating to one side, forward low speed range 1st speed pressure oil passage (4
4) is communicated with the other side of the shuttle valve (62). The reference numerals in the parentheses indicate the corresponding members of the embodiments described later.

[0008]

In the hydraulic control system for an automatic transmission according to the present invention as set forth in claim 1, when the reverse range is erroneously selected during forward traveling, the reverse range pressure is generated, but the reverse stage inhibition valve 36 is , The signal hydraulic control valve 22 causes the friction element 3 to
Switch to the side that shuts off the supply of reverse range pressure to 2.
As a result, since the friction element 32 is not fastened,
Shifting to the reverse gear during forward traveling is prevented. Further, at this time, since the oil pressure is not supplied to the first oil passage 18, the signal oil pressure control valve 22 causes the control valve 2 to operate.
Even if 0 is switched to either the side that connects the first oil passage 18 and the second oil passage 19 or the side that blocks the first oil passage 18, the first oil passage 18
Therefore, the hydraulic pressure is not supplied to the second oil passage 19.

Next, at the time of reverse, the reverse range is selected, so that the reverse range pressure is generated, and the signal hydraulic control valve 22 causes the reverse stage inhibition valve 36 to move the friction element 32.
Since the mode is switched to the side that supplies the reverse range pressure to, the shift to the reverse stage is performed. Further, at this time, the signal hydraulic control valve 22 causes the control valve 20 to switch to the opposite side to the case where the reverse range is erroneously selected during the forward traveling, but the hydraulic pressure is not supplied to the first oil passage 18. For the first
Oil pressure is not supplied from the oil passage 18 to the second oil passage 19.

Next, when the vehicle moves forward, the forward range is selected, and therefore the reverse range pressure is not generated. Therefore, no matter which side the reverse hydraulic pressure prohibiting valve 36 is switched to by the signal hydraulic pressure control valve 22, the friction element 32 is switched. The reverse range pressure is never supplied to. Therefore, shifting to the reverse gear is prevented. At this time, the hydraulic pressure is supplied to the first oil passage 18, and the signal hydraulic pressure control valve 22 controls the control valve 20.
Is switched to the side where the first oil passage 18 and the second oil passage 19 are communicated with each other, so that the hydraulic pressure is supplied from the first oil passage 18 to the second oil passage 19.

Thus, one signal hydraulic control valve 22
Thus, when the reverse range is erroneously selected during forward traveling, during reverse traveling, and during forward traveling, the reverse stage prohibition valve 36 and the control valve 20 can be controlled. Therefore, when the reverse range is selected during forward traveling. In addition, an operating oil chamber for making sure that the control valve 20 is switched to the side that shuts off the first oil passage 18 and the second oil passage 19 is specially provided with the control valve 20.
There is no need to install it in. Thereby, the control valve 20 can be downsized and the cost can be reduced.

Next, in the hydraulic control device for an automatic transmission according to the second aspect of the present invention, when the forward low speed range is selected, the reverse speed inhibition valve 36 causes the signal hydraulic control valve 22 to cause the friction element. 32 and the forward low speed range pressure oil passage 44 are connected to each other. Further, in the forward low speed range, the forward low speed range pressure is supplied to the forward low speed range pressure oil passage 44, so that the forward low speed range pressure is supplied to the friction element 32 and is engaged. As a result, the shift to the forward low speed stage is performed.

Next, when the reverse range is selected, the reverse-step inhibit valve 36 is controlled by the signal hydraulic control valve 22.
The friction element 32 and the reverse range pressure oil passage 42 are switched to the side in which they communicate with each other. Further, in the reverse range, since the reverse range pressure is supplied to the reverse range pressure oil passage 42, the reverse range pressure is supplied to the friction element 32, and the friction element 32 is engaged. As a result, the shift to the reverse gear is performed.

As described above, the reverse stage prohibition valve 36 is switched by the signal hydraulic pressure control valve 22 so that either the reverse range pressure or the forward low speed range pressure is applied to the friction element 32, and therefore this switching is performed. It is not necessary to provide a special device for the reverse stage prohibition valve 36. Thereby, the hydraulic control device 11 can be downsized.

Next, in the hydraulic control device for an automatic transmission according to the third aspect of the present invention, since the reverse range pressure oil passage 42 is cut off from the output oil passage 64 by the reverse gear prohibiting valve 60, L
The hydraulic pressure is not supplied to & R / B32. Therefore, since the friction element 32 is not engaged, it is possible to prevent shifting to the reverse gear during forward traveling.

At this time, since the signal oil pressure is supplied to the first signal pressure chamber 20a of the timing valve 20, the timing valve 20 operates by overcoming the elastic force of the first spring 50, and the first bypass oil passage 18 and the first bypass oil passage 18 are connected. The second bypass oil passage 19 is switched to the communicating state, but as described above, the shift valve 14 does not supply the hydraulic pressure to the clutch pressure oil passage 12 in the reverse range. Therefore, since the hydraulic pressure is not supplied to the clutch 10, the clutch 10 is never engaged.

When the reverse range is selected, the solenoid valve 22 is turned on, the drain circuit is opened, and
Since the signal oil pressure of the oil passage 26 is drained, the signal oil pressure is not supplied to the second signal pressure chamber 60a of the reverse stage prohibition valve 60, so that it is operated by the elastic force of the second spring 52 to output the oil oil passage 64. And the reverse range pressure oil passage 42 are connected to each other. In the reverse range, the shift valve 1
4, the hydraulic pressure is supplied to the reverse range pressure oil passage 42. As a result, the oil pressure is supplied to the output oil passage 64, so that the ball 62a of the shuttle valve 62 moves upward in FIG. 2 to switch the output oil passage 64 and the oil passage 68 into communication with each other. Therefore, the hydraulic pressure is supplied to the L & R / B 32,
The friction element 32 is fastened. As a result, the shift to the reverse gear is performed.

At this time, in the timing valve 20, since the drain circuit of the solenoid valve 22 is opened and the signal hydraulic pressure is not supplied to the first signal pressure chamber 20a of the solenoid valve 22, the first spring 50 is provided.
Is operated by the elastic force of the first bypass oil passage 18 and the second bypass oil passage 18.
The bypass oil passage 19 is switched off. In the reverse range, the shift valve 14 does not supply the hydraulic pressure to the clutch pressure oil passage 12. Therefore, since the hydraulic pressure is not supplied to the clutch 10, the clutch 1
0 will never sign.

[0019]

FIG. 1 shows the first embodiment of the present invention. The hydraulic control device 11 includes a clutch 10, a clutch pressure oil passage 12,
Shift valve 14, orifice 16, first bypass oil passage (first oil passage) 18, second bypass oil passage (second oil passage) 19, timing valve (control valve) 20, solenoid valve (signal hydraulic control valve) 22 , Pilot valve 24, manual valve 30, low and reverse brake (L & R / B) (friction element)
32, and reverse inhibit valve (REV INH
It has a valve) (reverse stage prohibition valve) 36, a reverse range pressure oil passage 42, and a forward low speed range first speed pressure oil passage 44, which are connected as shown.

The clutch 10 is engaged at the second speed or higher, and is connected to the shift valve 14 by the clutch pressure oil passage 12.

The manual valve 30 can supply the line pressure PL to the shift valve 14 and the reverse range pressure oil passage 42 according to the select position.

The shift valve 14 operates according to PL supplied from the manual valve 30 and can supply hydraulic pressure to the clutch pressure oil passage 12 and the forward low speed range first speed pressure oil passage 44, respectively.

The orifice 16 is a fixed throttle element provided in the clutch pressure oil passage 12 for reducing the shift shock.

First and second bypass oil passages 18 and 19
Is provided between these as an oil passage capable of bypassing the orifice 16 of the clutch pressure oil passage 12 via the timing valve 20.

The timing valve 20 has a first side on a side opposite to a side on which a signal hydraulic pressure from a solenoid valve 22 described later acts.
It is biased by a spring 50. The timing valve 20 is the first
When the spring 50 is extended (that is, when the solenoid valve 22 to be described later is on and the signal hydraulic pressure is not output)
In the state where the first bypass oil passage 18 and the second bypass oil passage 19 are shut off and the first spring 50 is contracted (that is, the signal hydraulic pressure is output when the solenoid valve 22 described later is in the off state). Time) so that the first bypass oil passage 18 and the second bypass oil passage 19 are in communication with each other,
It can be switched.

The solenoid valve 22 is communicated with the pilot valve 24 by an oil passage 26 having an orifice 28. When the solenoid valve 22 is turned on, a drain circuit is opened to drain the signal oil pressure of the oil passage 26, which is drained. When it is turned off, the drain circuit is closed and the signal oil pressure is supplied to the timing valve 20 and the REV / INH valve 36.

The pilot valve 24 can regulate the line pressure and output a constant signal hydraulic pressure (pilot pressure) required for shift control to the oil passage 26.

The L & R / B 32 is engaged in the first forward speed range and the reverse speed range, and is connected to the REV / INH valve 36 by the oil passage 34.

The REV / INH valve 36 is the solenoid valve 2
The side opposite to the side on which the signal hydraulic pressure from 2 acts is urged by the second spring 52. When the solenoid valve 22 is in the off state, the REV / INH valve 36 causes the second spring 52 to contract to connect the reverse range pressure oil passage 42 and the oil passage 34 to each other, and the solenoid valve 22 is in the on state. At times, the second spring 52 can be extended so that the forward low speed range first speed hydraulic passage 44 and the hydraulic passage 34 are brought into communication with each other.

Next, the operation of the first embodiment will be described. First, the operation during the engagement timing control of the clutch 10 when the D range is selected and the second speed or higher is described. When the engagement timing of the clutch 10 is delayed, the solenoid valve 22 is turned on, the drain circuit is opened, and the signal hydraulic pressure of the oil passage 26 is drained. As a result, since the signal hydraulic pressure is not supplied from the solenoid valve 22 to the first signal pressure chamber 20a of the timing valve 20, the timing valve 20 is actuated by the elastic force of the first spring 50, and the first bypass oil passage 18 and the second bypass oil passage 18 are bypassed. The oil passage 19 is switched to a cutoff state. In the D range, since the shift valve 14 supplies the hydraulic pressure to the clutch pressure oil passage 12, the hydraulic pressure is also supplied from the clutch pressure oil passage 12 to the first bypass oil passage 18, but the timing valve 20 causes the first bypass oil passage to flow. Since the oil passage 18 and the second bypass oil passage 19 are cut off, the hydraulic pressure is not supplied to the second bypass oil passage 19. Therefore, since only the oil pressure passing through the orifice 16 is supplied to the clutch 10, the clutch 10
The hydraulic pressure will be slowly supplied to. As a result, the engagement timing of the clutch 10 is delayed.

At this time, since the signal hydraulic pressure is not supplied from the solenoid valve 22 to the second signal pressure chamber 36a of the REV INH valve 36, the REV INH valve 36 is actuated by the elastic force of the second spring 52 and retracts from the oil passage 34. The range pressure oil passage 42 is switched to a communication state. However, as described above, in the D range, since the hydraulic pressure is not supplied from the shift valve 14 to the reverse range pressure oil passage 42, the hydraulic pressure is not supplied to the L & R / B 32. Therefore, the L & R / B 32 will not be engaged.

Next, when the engagement timing of the clutch 10 is advanced, the solenoid valve 22 is turned off and the drain circuit is closed. As a result, the signal hydraulic pressure is supplied to each of the first signal pressure chamber 20a of the timing valve 20 and the second signal pressure chamber 36a of the REV / INH valve 36. Therefore, the timing valve 20 operates by overcoming the elastic force of the first spring 50 to switch the first bypass oil passage 18 and the second bypass oil passage 19 into communication with each other. This allows
The hydraulic pressure supplied from the shift valve 14 to the clutch pressure oil passage 12 passes through the orifice 16 and is supplied to the clutch 10, and also passes through the first bypass oil passage 18 and the second bypass oil passage 19 to the clutch 10. Supplied. Therefore, since the hydraulic pressure is quickly supplied to the clutch 10, the engagement timing of the clutch 10 is advanced.

At this time, the REV / INH valve 36 operates by overcoming the elastic force of the second spring 52 by the signal oil pressure being supplied to the second signal pressure chamber 36a thereof, and moving forward with the oil passage 34. It is switched to a state in which it communicates with the low speed range 1st speed pressure oil passage 44. However, in the D range, since the hydraulic pressure is not supplied from the shift valve 14 to the forward low speed range first speed hydraulic passage 44, the signal hydraulic pressure is not supplied to the L & R / B 32. Therefore, the L & R / B 32 will not be engaged.

Next, the operation during the reverse speed prohibition control will be described. If the reverse range is erroneously selected during forward traveling, the solenoid valve 22 is turned off,
Close the drain circuit. As a result, the timing valve 20
Of the first signal pressure chamber 20a and the second of the REV INH valve 36
A signal hydraulic pressure is supplied to each of the signal pressure chambers 36a. Therefore, the REV / INH valve 36 operates by overcoming the elastic force of the second spring 52 to switch the oil passage 34 and the forward low speed range first speed oil passage 44 into a communication state. However, in the reverse range, the manual valve 30 does not supply the hydraulic pressure to the forward low speed range first speed hydraulic passage 44.
Therefore, since the hydraulic pressure is not supplied to the L & R / B32, the L & R / B32 is not engaged. As a result, it is possible to prevent the shift to the reverse gear when traveling forward.

At this time, since the signal oil pressure is supplied to the first signal pressure chamber 20a of the timing valve 20, the timing valve 20 operates by overcoming the elastic force of the first spring 50, and the first bypass oil passage 18 and the first bypass oil passage 18 are connected. Although it is switched to a state in which the second bypass oil passage 19 is communicated with, the hydraulic pressure is not supplied to the clutch pressure oil passage 12 by the shift valve 14 in the reverse range as described above. Therefore, since the hydraulic pressure is not supplied to the clutch 10, the clutch 10 is not engaged.

Next, the operation during the reverse control will be described. When the reverse range is selected, the solenoid valve 22 is turned on, the drain circuit is opened, and the signal hydraulic pressure of the oil passage 26 is drained. For this reason, the signal oil pressure is not supplied to the second signal pressure chamber 36a of the REV INH valve 36, so that the REV INH valve 36 is actuated by the elastic force of the second spring 52 to connect the oil passage 34 and the reverse range pressure oil passage 42. Switch to the state of communication. In the reverse range, the shift valve 14 supplies hydraulic pressure to the reverse range pressure oil passage 42. As a result, L & L passes through the reverse range pressure oil passage 42 and the oil passage 34.
Since hydraulic pressure is supplied to the R / B 32, the L & R / B 32 is engaged. Therefore, the shift to the reverse gear is performed.

At this time, in the timing valve 20, since the drain circuit of the solenoid valve 22 is opened, the signal hydraulic pressure is not supplied to the first signal pressure chamber 20a of the timing valve 20. Therefore, the timing valve 20 operates by the elastic force of the first spring 50 and switches to a state in which the first bypass oil passage 18 and the second bypass oil passage 19 are shut off. In the reverse range, the shift valve 14 does not supply the hydraulic pressure to the clutch pressure oil passage 12. For this reason, since the hydraulic pressure is not supplied to the clutch 10, the clutch 10 is not engaged.

Next, the operation during the 1-2 shift control will be described. When the forward low speed range is selected and the vehicle is shifted to the 1st speed, the solenoid valve 22 is off, and the signal hydraulic pressure is supplied to the second signal pressure chamber 36a of the REV / INH valve 36. As a result, the oil passage 34 and the forward low speed range first speed pressure oil passage 44 are in communication with each other. Further, the shift valve 14 is in the state of being shifted to the 1st speed, and therefore supplies the hydraulic pressure to the forward low speed range 1st speed pressure oil passage 44. Therefore, the L & R / B 32 is fastened. When shifting from this state to the second speed, the solenoid valve 22 is turned on, the drain circuit is opened,
Drain the signal hydraulic pressure. As a result, REV INH
Since the signal hydraulic pressure is not supplied to the second signal pressure chamber 36a of the valve 36, the valve 36 operates by the elastic force of the second spring 52 and switches to a state in which the oil passage 34 and the reverse range pressure oil passage 42 are communicated with each other. . Therefore, the hydraulic pressure is drained from the L & R / B32, and the fastening of the L & R / B32 is released. After that, the shift valve 14 is operated to set the second speed state, and the hydraulic pressure is supplied to the clutch pressure oil passage 12. The timing valve 20 is
Since the solenoid valve 22 is in the ON state and the drain circuit is opened, the signal hydraulic pressure is not supplied to the first signal pressure chamber 20a of the solenoid valve 22. Therefore, the timing valve 20 has the first
The first bypass oil passage 1 operates by the elastic force of the spring 50.
8 and the second bypass oil passage 19 are switched off. This allows the clutch 1 to pass through the orifice 16.
Since the hydraulic pressure is supplied to 0, the clutch 10 is slowly engaged.

Since the clutch 10 can be engaged after the L & R / B 32 is released in this manner, 1-2
Since it is possible to prevent an interlock that occurs when the release of the L & R / B 32 is performed later than the engagement of the clutch 10 during a gear shift, a strong sense of deceleration does not occur.

FIG. 2 shows a second embodiment. This hydraulic control device 70 uses the REV / INH valve 36 of the first embodiment as a REV / INH valve 60 having a drain port 66 as a port communicating with the forward low speed range first speed hydraulic passage 44. A shuttle valve 62 is provided between the INH valve 60 and the L & R / B 32, the output oil passage 64 of the REV / INH valve 60 is connected to one side of the shuttle valve 62, and the forward low speed range first speed oil passage 44 is shuttled. It communicates with the other side of the valve 62. Since the other structure is the same as that of the first embodiment, the description of the same parts as those of the first embodiment will be omitted in the following description.

The REV / INH valve 60 is biased by the second spring 52 on the side facing the second signal pressure chamber 60a on which the signal oil pressure from the solenoid valve 22 acts, as in the first embodiment. In the REV / INH valve 60, when the solenoid valve 22 is in the off state, the signal oil pressure is supplied from the solenoid valve 22 to the second signal pressure chamber 60a, so that the second spring 52 contracts and the drain port 66 and the output oil passage 64 are compressed. When the solenoid valve 22 is in the ON state, since the signal oil pressure is not supplied from the solenoid valve 22 to the second signal pressure chamber 60a, the second spring 52 extends and the backward range pressure oil passage It is switchable so that 42 and the output oil passage 64 are brought into communication with each other.

When oil pressure is supplied to the output oil passage 64, the shuttle valve 62 raises the ball 62a of the shuttle valve 62 in FIG. 2 to switch the output oil passage 64 and the oil passage 68 into communication with each other. To supply hydraulic pressure to L & R / B32.
When the hydraulic pressure is supplied to the forward low speed range first speed pressure oil passage 44, the ball 62a thereof is lowered in FIG. 2 to bring the forward low speed range first speed pressure oil passage 44 and the oil passage 68 into communication with each other. By switching, it is possible to supply hydraulic pressure to the L & R / B 32.

Next, the operation of the second embodiment will be described. First, regarding the operation during the engagement timing control of the clutch 10 when the D range is selected by the manual valve 30 and the second speed or higher, the REV / INH valve 60 is operated when the solenoid valve 22 is turned on. Is the same as that of the first embodiment except that the drain port 66 and the output oil passage 64 are switched to the communicating state.

Next, the operation during the reverse gear prohibition control will be described. If the reverse range is selected by the manual valve 30 during forward traveling, the solenoid valve 22 is turned off and the drain circuit is closed. As a result, the first signal pressure chamber 20a of the timing valve 20 and the RE
The signal hydraulic pressure is supplied to the second signal pressure chamber 60a of the V.INH valve 60. Therefore, the REV / INH valve 60 operates by overcoming the elastic force of the second spring 52 to switch the drain port 66 and the output oil passage 64 into a communication state. At this time, since the shift valve 14 is selected in the reverse range, hydraulic pressure is supplied to the reverse range pressure oil passage 42.
As described above, the reverse range pressure oil passage 42 is blocked from the output oil passage 64 by the REV / INH valve 60, so
The hydraulic pressure is not supplied to & R / B32. Therefore, since the L & R / B 32 is not engaged, it is possible to prevent the shift to the reverse gear during forward traveling.

At this time, since the signal oil pressure is supplied to the first signal pressure chamber 20a of the timing valve 20, the timing valve 20 operates by overcoming the elastic force of the first spring 50, and the first bypass oil passage 18 and the first bypass oil passage 18 are connected. The second bypass oil passage 19 is switched to the communicating state, but as described above, the shift valve 14 does not supply the hydraulic pressure to the clutch pressure oil passage 12 in the reverse range. Therefore, since the hydraulic pressure is not supplied to the clutch 10, the clutch 10 is never engaged.

Next, the operation during the reverse control will be described. When the reverse range is selected, the solenoid valve 22 is turned on, the drain circuit is opened, and the oil passage 26 is opened.
Drain the signal hydraulic pressure of. Therefore, REV INH
Since the signal hydraulic pressure is not supplied to the second signal pressure chamber 60a of the valve 60, the valve 60 operates by the elastic force of the second spring 52,
The output oil passage 64 and the reverse range pressure oil passage 42 are switched to a communication state. In the reverse range, the shift valve 14 supplies hydraulic pressure to the reverse range pressure oil passage 42.
As a result, the oil pressure is supplied to the output oil passage 64, so that the ball 62a of the shuttle valve 62 moves upward in FIG. 2 to switch the output oil passage 64 and the oil passage 68 into communication with each other. Therefore, the hydraulic pressure is supplied to the L & R / B32, and the L & R / B32 is engaged. As a result, the shift to the reverse gear is performed.

At this time, in the timing valve 20, since the drain circuit of the solenoid valve 22 is opened and the signal hydraulic pressure is not supplied to the first signal pressure chamber 20a of the solenoid valve 22, the first spring 50 is not provided.
Is operated by the elastic force of the first bypass oil passage 18 and the second bypass oil passage 18.
The bypass oil passage 19 is switched off. In the reverse range, the shift valve 14 does not supply the hydraulic pressure to the clutch pressure oil passage 12. Therefore, since the hydraulic pressure is not supplied to the clutch 10, the clutch 1
0 will never sign.

[0048]

According to the present invention as set forth in claim 1, when the reverse range is selected, the hydraulic pressure is prevented from being supplied to the first oil passage. The hydraulic pressure is not supplied from the first oil passage to the second oil passage regardless of which of the side that connects the first oil passage and the second oil passage and the side that shuts off the first oil passage. For this reason, one signal hydraulic control valve can control the reverse stage prohibition valve and the control valve when the reverse range is erroneously selected during forward traveling, during backward traveling, and during forward traveling. When the reverse range is erroneously selected, it is necessary to specially provide the control valve with an oil chamber for operation so that the control valve always switches to the side that shuts off the first oil passage and the second oil passage. There is no. As a result, the control valve can be downsized and the cost can be reduced.

According to the second aspect of the present invention, the reverse stage prohibition valve is switched by the signal hydraulic control valve so that either the reverse range pressure or the forward low speed range pressure acts on the friction element. . Therefore, it is not necessary to provide a special device for performing this switching on the reverse stage prohibition valve.
As a result, the hydraulic control device can be downsized.

According to the third aspect of the present invention, since the reverse range pressure oil passage is cut off from the output oil passage by the reverse stage prohibition valve, the hydraulic pressure is not supplied to the friction element, and the friction element is not supplied. Since the elements are not fastened, it is possible to prevent shifting to the reverse gear during forward traveling.

[Brief description of drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

[Explanation of symbols]

18 1st bypass oil passage (1st oil passage) 19 Second bypass oil passage (second oil passage) 20 Timing valve (control valve) 22 Solenoid valve (Signal hydraulic control valve) 32 L & R / B (friction element) 36 REV INH valve (reverse stage prohibition valve) 42 Reverse range pressure oil passage 44 Forward low speed range pressure oil passage

Claims (3)

(57) [Claims] 1. The hydraulic pressure when the reverse range is selected.
The control valve (20) that can switch between the communication side that communicates the second oil passage (19) with the first oil passage (18) that is not supplied with the oil and the shut-off side that blocks this communication, and the reverse range The reverse range inhibition valve (3) that can switch the reverse range pressure generated when selected to the friction element (32) between the supply side for supplying and the cutoff side for blocking.
6 , 60 ), the control valve (20) and the reverse stage prohibition valve (36 , 6)
0 ), a signal hydraulic control valve (22) capable of supplying and shutting off a signal hydraulic pressure for activating these switchings, and a hydraulic control device for an automatic transmission, comprising: the first oil passage (18) and the second hydraulic passage (18) . The oil passage (19) is
Provided on the oil passage (12) for supplying oil pressure to the latch (10)
An oil pressure control device for an automatic transmission, which is an oil passage capable of bypassing the orifice (16) . 2. The reverse range prohibiting valve (36) is provided when a reverse range pressure oil passage (42) to which the reverse range pressure is supplied to the friction element (32) and a forward low speed range are selected. The forward low speed range pressure can be switched so as to communicate with either one of the forward low speed range pressure oil passages (44), and the reverse stage inhibition valve (36) is the signal hydraulic control valve. (2
In one of the cases where the signal oil pressure from 2) is supplied and cut off, the friction element (32) is switched to the side in which the reverse range pressure oil passage (42) is communicated, while the signal oil pressure control valve ( 22) is configured to switch to a side in which the forward low speed range pressure oil passage (44) communicates with the friction element (32) in the other case where the signal hydraulic pressure from 22) is supplied and cut off. The hydraulic control device for the automatic transmission according to claim 1. 3. The reverse speed prohibiting valve is a forward low speed valve for the reverse speed prohibiting valve.
Drain the port communicating with the first speed oil passage (44).
And the reverse stage prohibition valve (60) which is a port (66)
Then, the reverse stage prohibition valve (60) and the friction element (32)
A shuttle valve (62) is provided between
The output oil passage (64) of (60) is connected to the shuttle valve (62).
The forward low speed range 1st speed pressure oil passage (44).
A communication valve according to claim 1, which communicates with the other side of the shuttle valve (62).
Hydraulic control device for automatic transmission.