JP2764185B2 - Automatic transmission safety device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for an automatic transmission, and particularly to a safety device for an automatic transmission when a shift servo valve for switching a forward / reverse switching mechanism provided in the automatic transmission is not operated. The present invention relates to a safety device for an automatic transmission that secures safety by making it impossible to start.

[Conventional technology]

In vehicles such as automobiles, a transmission is provided in order to appropriately extract the driving force generated by the internal combustion engine in accordance with the traveling state. The transmission includes a manual transmission in which the driver manually converts the driving force of the internal combustion engine to a required gear ratio according to the traveling state and takes out the driving force, or automatically converts the driving force of the internal combustion engine according to the traveling state according to the required gear ratio. There is an automatic transmission or the like that converts and takes out the data.

An automatic transmission is disclosed in Japanese Patent Publication No. 64-11858. The automatic transmission disclosed in this publication is configured such that at low load and low rotation speed, the gear is shifted up earlier on the low rotation side than during normal driving, and the gear stage is maintained on the higher rotation side than during normal driving. The aim was to improve the fuel consumption rate during traffic congestion while ensuring a good driving feeling during steady driving, and to improve the driving performance by avoiding unnecessary shift-up during temporary acceleration during traffic congestion. Things.

Japanese Patent Publication No. 64-1703 discloses a hydraulic control device for controlling an automatic transmission by hydraulic pressure.
The hydraulic control device for an automatic transmission disclosed in this publication is a hydraulic control device for an automatic transmission configured to supply oil pressure to a friction element via a pressure reducing valve. By communicating through a stop valve and discharging the oil pressure from the friction element through the check valve, when the pressure reducing valve is stopped due to a failure or the like, the oil pressure of the friction element is checked. Through which the gearbox is reliably discharged to prevent the occurrence of a shift shock due to a delay in the opening operation of the friction element.

[Problems to be solved by the invention]

By the way, some conventional automatic transmissions mechanically perform a switching operation of a forward / reverse switching mechanism for switching, for example, a forward / reverse engagement state of the automatic transmission by a shift mechanism.
In the case of such a mechanical shift mechanism, there is a problem that a smooth shift operation cannot be obtained.

Therefore, the shift mechanism switches the manual shift valve to supply and discharge the hydraulic pressure to the shift servo valve, and the shift servo valve switches the forward / backward switching mechanism for switching the forward / backward engagement state of the automatic transmission. There is. According to such a hydraulic servo type shift mechanism, the shift operation can be performed smoothly.

However, in the shift mechanism of the hydraulic servo type, the shift servo valve may be in an inoperative state due to some mechanical cause, and the switching between the forward and backward engagement states may not be performed. If the start operation is performed to cause the vehicle to travel when the shift servo valve is not operated, there is a disadvantage that the start direction of the vehicle is opposite to the operation direction and safety is impaired.

[Object of the invention]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a safety device for an automatic transmission in which safety is ensured by disabling a vehicle when a shift servo valve for switching a forward / reverse switching mechanism provided in the automatic transmission is inoperative. It is to realize.

[Means for solving the problem]

In order to achieve this object, the present invention relates to an automatic transmission that automatically converts a driving force of an internal combustion engine according to a required gear ratio in accordance with a running state of a vehicle and takes out the driving force. A hydraulic clutch which is engaged and disengaged by supplying and discharging hydraulic clutch pressure to intermittently intermittently operate, and a forward / backward switching mechanism for switching the forward / backward engagement state of the automatic transmission is provided, and the forward / backward switching mechanism is switched. A shift servo valve for supplying and discharging a line pressure as a hydraulic pressure is provided, and the shift servo valve is provided with a piston slidably in a cylinder of a valve body, and the piston partitions a first chamber and a second chamber in the cylinder. The piston is connected to one end of the shift servo rod and is provided at the other end of the shift servo rod. A manual operation that is switched by a shift mechanism of the automatic transmission to supply and discharge hydraulic pressure to and from the hydraulic clutch and supply and discharge hydraulic pressure to and from the shift servo valve. A shift valve is provided. In this manual shift valve, a spool valve body, one end of which is connected to the operating rod of the shift mechanism, is slidably provided in a slide hole of the valve body, and the valve body of the manual shift valve slides. First to seventh grooves are provided on the inner peripheral surface of the moving hole, and first to fifth large diameter portions are provided on the spool valve body so as to slidably contact the inner peripheral surface of the sliding hole. A first groove portion of the manual shift valve provided in communication with a first chamber of the shift servo valve through a first passage; A passage for supplying a hydraulic line pressure to the second groove of the shift valve; and a third groove of the manual shift valve connected to a second chamber of the shift servo valve through a second passage. A fourth groove portion of the valve is provided in communication with an oil pan of the automatic transmission, and a sixth groove portion of the manual shift valve is provided in communication with a passage for supplying hydraulic clutch pressure, and a fifth groove portion of the manual shift valve is provided. And a seventh groove are provided in communication with the third passage and the fourth passage, respectively, and the third passage and the fourth passage are connected to the fifth passage.
A hydraulic supply that is provided in communication with a hydraulic chamber of the hydraulic clutch through a passage, and that stops supply of hydraulic pressure to the hydraulic clutch to prevent engagement of the hydraulic clutch when the shift servo valve is inoperative. Provide a stop mechanism,
The valve body of the hydraulic supply stop mechanism is provided integrally with the valve body of the shift servo valve, and a spool valve body slidably mounted in a slide hole of the valve body of the hydraulic supply stop mechanism is provided with the shift servo valve. The first to sixth grooves are formed on the inner peripheral surface of the sliding hole of the valve body of the hydraulic supply stop mechanism, and are provided on the spool valve body of the hydraulic supply stop mechanism. First to third large diameter portions are provided in sliding contact with the inner peripheral surface of the moving hole, and first and second small diameter portions are provided between the first to third large diameter portions, respectively. A groove portion is provided in communication with an oil pan of the automatic transmission, a second groove portion of the hydraulic supply stop mechanism is provided in communication with a fifth passage of the hydraulic clutch through a sixth passage, and a third groove of the hydraulic supply stop mechanism is provided. Insert the groove into the manual A fourth groove of the hydraulic supply stop mechanism is provided in communication with a fourth passage of the shift valve, a fourth groove of the hydraulic supply stop mechanism is provided in communication with a third passage of the manual shift valve, and a fifth groove of the hydraulic supply stop mechanism is provided with a seventh passage. The hydraulic clutch is provided in communication with a fifth passage, the sixth groove of the hydraulic supply stop mechanism is provided in communication with the oil pan of the automatic transmission, and the hydraulic supply stop mechanism is configured to operate a manual shift valve by the shift mechanism. By switching to the reverse range and supplying the hydraulic pressure line pressure to the second chamber of the shift servo valve through the second passage, and discharging the hydraulic pressure line pressure of the first chamber of the shift servo valve through the first passage. When the forward / reverse switching mechanism is switched from the forward engagement state to the reverse engagement state, the shift servo valve piston becomes inoperative and the shift servo When the forward / reverse switching mechanism is not switched from the forward engagement state to the reverse engagement state by the rod, the second large diameter portion of the spool valve body of the hydraulic supply stop mechanism is used to prevent engagement of the hydraulic clutch. The fourth passage and the sixth passage are closed to stop the supply of the hydraulic pressure to the hydraulic chamber of the hydraulic clutch, and the third small passage communicates the third passage with the seventh passage. The hydraulic pressure in the hydraulic chamber of the hydraulic clutch is discharged to the oil pan via the third small diameter portion of the manual shift valve, and the hydraulic supply stop mechanism switches the manual shift valve to the drive range by the shift mechanism. A first passage supplies a line pressure which is a hydraulic pressure to a first chamber of the shift servo valve, and a second passage supplies a line pressure which is a hydraulic pressure of a second chamber of the shift servo valve. When the forward / backward switching mechanism is switched from the reverse engagement state to the forward engagement state by discharging the hydraulic pressure, the piston of the shift servo valve becomes inoperative and the forward / backward switching mechanism is moved backward by the shift servo rod. When the engagement state is not switched to the forward engagement state, the third passage and the seventh passage are formed by the second large diameter portion of the spool valve body of the hydraulic supply stop mechanism so as to prevent the engagement of the hydraulic clutch. To shut off the supply of the hydraulic pressure to the hydraulic chamber of the hydraulic clutch, and communicate the fourth passage and the sixth passage with the first small-diameter portion so that the hydraulic barrel in the hydraulic chamber of the hydraulic clutch is closed. The pressure is discharged to an oil pan through a fourth small diameter portion of the manual shift valve.

[Action]

According to the configuration of the present invention, the automatic transmission switches the manual shift valve to the reverse range or the drive range by the shift mechanism, and supplies and discharges the line pressure as the hydraulic pressure to the first chamber or the second chamber of the shift servo valve. When the forward / reverse switching mechanism is switched from the forward engagement state to the reverse engagement state or from the backward engagement state to the forward engagement state, the piston of the shift servo valve becomes inoperative and the forward / backward movement is performed by the shift servo rod. When the switching mechanism is not switched, the sixth and third communication ports are connected to the fifth passage of the hydraulic clutch by the first to third large diameter portions and the first and second small diameter portions of the spool valve body of the hydraulic supply stop mechanism. The seven passages are switched to the third and fourth passages communicating with the manual shift valve, and the supply of the hydraulic pressure to the hydraulic chamber of the hydraulic clutch is stopped. Together by discharging the hydraulic serving clutch pressure of the hydraulic chamber, it is possible to cut off the driving force to the output of the automatic transmission and prevents the engagement of the hydraulic clutch.

〔Example〕

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

1 to 9 show an embodiment of the present invention.
In FIG. 9, reference numeral 2 denotes an automatic transmission. This automatic transmission 2 continuously and steplessly changes the gear ratio by means of a belt, and automatically converts the driving force of an internal combustion engine (not shown) according to the required gear ratio according to the running state of a vehicle (not shown). And take it out.

The automatic transmission 2 includes a drive-side pulley 6 on an input shaft 4 connected to an internal combustion engine (not shown) and a driven shaft pulley 10 on an output shaft 8, and the drive-side pulley 6 and the driven-side pulley
A belt 12 is wrapped between 10 and 10.

The drive-side pulley 6 has a drive-side fixed pulley portion 14 fixed to the input shaft 4 and a drive-side movable pulley portion 16 mounted on the input shaft 4 so as to be movable in the axial direction and non-rotatably. doing. The driven side pulley 10 includes a driven side fixed pulley portion 18 fixed to the output shaft 8 and a driven side movable pulley portion mounted on the output shaft 8 so as to be axially movable and non-rotatable. And 20.

The drive side movable pulley piece 16 has a drive side hydraulic chamber 22. The driven-side movable pulley piece 20 has a driven-side hydraulic chamber 24. The hydraulic pressure receiving area of the drive side movable pulley portion 16 of the drive side hydraulic chamber 22 is set to be larger than the hydraulic pressure receiving area of the driven side pulley portion 20 of the driven hydraulic chamber 24. As a result, the belt ratio as the gear ratio is changed by controlling the hydraulic pressure acting on the drive-side hydraulic chamber 22.

In the driven side hydraulic chamber 24, the driven side movable pulley part 20 is disposed in a direction in which the groove width between the driven side fixed pulley part 18 and the driven side movable pulley part 20 is reduced. An urging means 26 comprising an urging spring or the like is provided. This urging means 26
When the hydraulic pressure is low, such as at the time of starting, a large speed ratio on the full low side is maintained, and the holding force of the belt 12 is maintained to prevent slippage.

The input shaft 4 is provided with an oil pump 28. The oil pump 28 pumps oil stored in the oil pan 29. The oil pump 28 is provided in communication with the drive side and driven side hydraulic chambers 22 and 24 through first and second oil passages 30 and 32, respectively. In the middle of the first oil passage 30, a primary pressure control valve for controlling a primary pressure, which is an input shaft sheave pressure.
Intermediate 32. In the first oil passage 30 closer to the oil pump 28 than the primary pressure control valve 34, a constant pressure control valve 36 for controlling the line pressure to a constant control oil pressure and taking out the same is provided in communication therewith. The primary pressure control valve 34 has a third
The first three-way solenoid valve 40 for primary pressure control is provided in communication with the oil passage 38.

A line pressure control valve 42 having a relief valve function for controlling a line pressure as a pump pressure is provided in the middle of a second oil passage 32 communicating the oil pump 28 and the driven side hydraulic chamber 24.
Are provided in communication. The line pressure control valve 42 is provided with a second three-way solenoid valve 46 for line pressure control in communication with a fourth oil passage 44.

Further, a clutch pressure control valve for controlling a clutch pressure acting as a hydraulic pressure acting on a hydraulic clutch 58, which will be described later, in the second oil passage 32 on the driven side hydraulic chamber 24 side of the portion where the line pressure control valve 42 communicates. 48 are connected. The clutch pressure control valve 48 is provided with a third three-way solenoid valve 52 for clutch pressure control in communication with a fifth oil passage 50.

Further, the constant pressure control oil pressure taken out from the constant pressure control valve 36 is supplied to the primary pressure control valve 34, the primary three-way solenoid valve 40 for primary pressure control, the line pressure control valve 42, and the second three-way solenoid valve 46 for line pressure control, And clutch pressure control valve
These valves 36, 34, 40, 42, 46, 48, 52 are connected to each other by a sixth oil passage 54 so as to be supplied to the 48 and the third three-way solenoid valve 52 for clutch pressure control, respectively.

The clutch pressure control valve 48 is provided in communication with a clutch hydraulic chamber 60 of a hydraulic clutch 58 through a seventh oil passage 56. A pressure sensor 62 is provided in communication with the seventh oil passage 56.

The hydraulic clutch 58 includes an input casing 64 attached to the output shaft 8, the clutch hydraulic chamber 60 provided in the casing 64, and a piston pushed by hydraulic pressure acting on the clutch hydraulic chamber 60. 66 and this piston
An annular spring 68 that urges the piston 66 in the retreating direction, a first pressure plate 70 that can be retracted by the pushing force of the piston 66 and the urging force of the annular spring 68, and a friction plate 72 on the output side. And a second pressure plate 74 fixed to the casing 64.

The hydraulic clutch 58 is provided in communication with the output shaft 8 and a final output shaft 76 rotatably fitted to the output shaft 8.
In this hydraulic clutch 58, when the hydraulic pressure acting on the clutch hydraulic chamber 60 is increased, the piston 66 is pushed forward to bring the first pressure plate 70 and the second pressure plate 74 into close contact with the friction plate 72 and engage therewith. It operates, and it becomes a so-called clutch connection state. On the other hand, when the clutch pressure acting on the clutch hydraulic chamber 60 is reduced, the piston 66 is retired by the urging force of the annular spring 68 to separate the first pressure plate 70 and the second pressure plate 74 from the friction plate 72. To perform a disengagement operation, so that a so-called clutch disengagement state occurs. By the disengagement operation of the hydraulic clutch 58,
The driving force output from the output shaft 8 of the automatic transmission 2 to the final output means 6 is intermittent.

The final output shaft 76 is connected to a drive wheel (not shown) via an intermediate shaft 78. Between the final output shaft 76 and the intermediate shaft 78, a forward / reverse switching mechanism 80 for switching the forward / backward engagement state is provided. The forward / reverse switching mechanism 80 includes a forward gear train 82, a reverse gear train 84, and a switching sleeve 86. The forward gear train 82 includes a forward output gear 88 fixed to the final output shaft 76, a forward switching gear 90 rotatably supported by the intermediate shaft 78 so as to mesh with the forward output gear 88, and , Consisting of The reverse gear train 84 includes a reverse output gear 92 fixed to the final output shaft 78, a reverse switching gear 94 rotatably supported by the intermediate shaft 78, a reverse output gear 92, and a reverse And an idler gear 96 for meshingly connecting the switching gear 94 for use. The switching sleeve 86 is mounted on the intermediate shaft 78 so as to be axially movable and non-rotatable, so that one of the forward switching gear 90 and the reverse switching gear 92 cannot be rotated on the intermediate shaft 78 by axial movement. To switch the forward / backward engagement state.

A driving-side rotation speed sensor 98 for detecting the rotation speed of the driving-side pulley 6 is provided, and a driven-side rotation speed sensor 100 for detecting the rotation speed of the driven-side pulley 10 is provided. A maximum output speed sensor 102 to be detected is provided. Various signals such as carburetor throttle opening, carburetor idle position, accelerator pedal signal, brake signal, power mode option signal, shift lever position, etc. are input and controlled in accordance with the signals from the pressure sensor 62 and the rotation speed sensors 98 to 102. A control unit 104 is provided as control means for performing the control.

The control unit 104 controls the automatic transmission 2 based on various input signals.
The first three-way solenoid valve 40 for primary pressure control, the second three-way solenoid valve 46 for line pressure control, and the third three-way solenoid valve for clutch pressure control are used to control the belt ratio and clutch engagement / disengagement state in various control modes. Controls the opening and closing operation of 52.

In order to switch the forward / reverse switching mechanism 80, a shift servo valve 106 for supplying and discharging hydraulic pressure is provided. The shift servo valve 106 has a valve body 108 as shown in FIG.
A piston 112 is slidably provided in the cylinder 110, and one end of a shift servo rod 114 is connected to the piston 112. A switching sleeve 86 of the forward / reverse switching mechanism 80 is provided on the other end of the shift servo rod 114. The shift fork 116 to be engaged with is fixedly provided.

Shift servo valve 106 has a piston in cylinder 110
When the hydraulic pressure is supplied to the first chamber 118 partitioned by the second chamber 120 and the hydraulic pressure in the second chamber 120 is discharged, the piston 112
Moves the shift servo rod 114 in the direction of arrow A, moves the switching sleeve 86 to the forward switching gear 90 side by the shift fork 116, rotatably connects the forward switching gear 90 to the intermediate shaft 78, and engages the forward engagement. Switch to state. On the other hand, when the hydraulic pressure is supplied to the second chamber 120 defined by the piston 112 in the cylinder 110 and the hydraulic pressure in the first chamber 118 is discharged, the shift servo valve 106 The switch sleeve 86 is moved in the direction of arrow B to move the switching sleeve 86 to the reverse switching gear 94 by the shift fork 116, and the reverse switching gear 94 is non-rotatably connected to the intermediate shaft 78 to switch to the reverse engagement state.

In order to supply / discharge hydraulic pressure to / from the hydraulic chamber 60 of the hydraulic clutch 58 and supply / discharge hydraulic pressure to / from the shift servo valve 106,
A manual shift valve 126 that is switched by an operation rod 124 of a shift mechanism 122 of the automatic transmission 2 is provided.

As shown in FIGS. 3 to 7, the manual shift valve 126 has a spool valve body 132 in a sliding hole 130 of a valve body 128.
Is slidably mounted. The valve body 128 is provided with annular first to seventh groove portions 134 to 146 on the inner peripheral surface of the sliding hole 130. The spool valve element 132 has one end connected to the operating rod 124 of the shift mechanism 122,
The first large diameter portion 148 to the fifth large diameter portion 156 are provided in sliding contact with the inner peripheral surface of the sliding hole 130, and the first large diameter portion 148 to the fifth large diameter portion 148 are formed.
Between 156, a first small diameter portion 158 to a fourth small diameter portion 164 are provided.

The first groove portion 134 provided in the valve body 128 of the manual shift valve 126 communicates with the first passage 166.
The first passage 166 is provided in the first chamber 1 of the shift servo valve.
Connected to 18. The manual shift valve 126
The second groove 134 is communicated with the second oil passage 32,
A line pressure as a hydraulic pressure discharged from the oil pump 28 is supplied. The third groove 138 of the manual shift valve 126 includes:
It is connected to the second passage 168. The second passage 168 communicates with the second chamber 120 of the shift servo valve 106. The fourth groove 140 of the manual shift valve 126 communicates with the oil pan 29.

Further, a fifth groove 142 provided in the valve body of the manual shift valve 126 is communicated with the third passage 170.
The sixth groove portion 144 of the manual shift valve 126 is connected to the seventh oil passage 56, and is supplied with a hydraulic pressure acting on the hydraulic clutch 58. The seventh groove 146 of the manual shift valve 126 communicates with the fourth passage 172. The hydraulic chamber 60 of the hydraulic clutch 58 is
The passage 170 and the fourth passage 172 supply and discharge the clutch pressure as a hydraulic pressure through the fifth passage 174.

In order to prevent the engagement of the hydraulic clutch 58 when the shift servo valve 106 is not operated, a hydraulic supply stop mechanism 176 for stopping supply of hydraulic pressure to the hydraulic chamber 60 of the hydraulic clutch 58 is provided.

The hydraulic supply stop mechanism 176 is connected to the shift servo valve 106
Are provided integrally. That is, the hydraulic supply stop mechanism 17
Reference numeral 6 has a spool valve element 182 slidably mounted in a sliding hole 180 of a valve body 178 provided integrally with a valve body 108 of the shift servo valve 106. This spool valve element 182
Are formed integrally with the shift servo rod 114. On the inner peripheral surface of the sliding hole 180 of the valve body 178,
An annular first groove portion 184 to a sixth groove portion 194 are provided. The spool valve element 182 is connected to an inner peripheral surface of a sliding hole 180 by a first
A large-diameter portion 196 to a third large-diameter portion 200 are provided, and a first small-diameter portion 202 to a second large-diameter portion 200 are provided between the first to third large-diameter portions 196 to 200, respectively.
A small diameter portion 204 is provided.

The first groove 184 provided in the valve body 178 of the hydraulic pressure supply stop mechanism 176 is communicated with the oil pan 29. The second groove 186 of the hydraulic pressure supply stop mechanism 176 is connected to the fifth passage 174 by a sixth passage 206. The third groove 188 of the hydraulic pressure supply stop mechanism 176 communicates with the fourth passage 172. The fourth groove passage 190 of the hydraulic supply stop mechanism 176
Is communicated with the third passage 170. The fifth groove 192 of the hydraulic pressure supply stop mechanism 176 is connected to the fifth passage 174 via a seventh passage 208. Hydraulic supply stop mechanism 1
The sixth groove 194 of 76 is connected to the oil pan 29.

 Next, the operation will be described.

The driving force of the internal combustion engine mounted on the vehicle is controlled by the automatic transmission 2
Is converted into a desired torque / rotational speed and is taken out to drive a drive wheel (not shown).

In such an automatic transmission 2, when the automatic transmission 2 is shifted to the parking range P by the shift mechanism 122, as shown in FIG.
The first small diameter portion 158 of the spool valve body 132
6 to the oil pan 29 side, and the second small diameter portion 160
The passage 168 communicates with the second oil passage 32, the seventh oil passage 56 is closed by the fourth large diameter portion 154 and the fifth large diameter portion 156, and the third passage 170 is closed by the third small diameter portion 162 on the oil pan 29 side. And the fourth passage 172 is communicated to the oil pan side by the outer end of the fifth large-diameter portion 156.

As a result, the shift servo valve 106 discharges the line pressure of the first chamber 118 and supplies the line pressure to the second chamber 120, so that the piston 112 moves the shift servo rod 114 in the direction of arrow B, and the shift fork 116 As a result, the switching sleeve 86 is moved to the reverse switching gear 94 side, the reverse switching gear 94 is non-rotatably connected to the intermediate shaft 78, and switched to the reverse engagement state.

At this time, the hydraulic supply stop mechanism 176
The fourth passage 172 and the sixth passage 206 are communicated with each other by the first small diameter portion 202, but the manual shift valve 126 closes the seventh oil passage 56 and moves the third passage 170 and the fourth passage 172 to the oil pan. It communicates with the 29 side.

For this reason, since the clutch pressure is not supplied to the hydraulic chamber 60 of the hydraulic clutch 58, the hydraulic clutch 58 is not engaged, the driving force output from the automatic transmission 2 is cut off, and the vehicle cannot move backward.

When the automatic transmission 2 is shifted to the reverse range R by the shift mechanism 122, the manual shift valve 126 is moved to the first small diameter portion 158 of the spool valve body 132 as shown in FIG.
Thus, the first passage 166 communicates with the oil pan 29 side, the second small diameter portion 160 communicates the second passage 168 with the second oil passage 32, and the third small diameter portion 162 connects the third passage 170 with the oil pan 29 side. The fourth passage 172 communicates with the seventh oil passage 56 through the fourth small-diameter portion 164.

As a result, the shift servo valve 106 discharges the line pressure of the first chamber 118 and supplies the line pressure to the second chamber 120, so that the piston 112 moves the shift servo rod 114 in the direction of arrow B, and the shift fork 116 As a result, the switching sleeve 86 is moved to the reverse switching gear 94 side, the reverse switching gear 94 is non-rotatably connected to the intermediate shaft 78, and switched to the reverse engagement state.

At this time, the hydraulic supply stop mechanism 176
The fourth passage 172 and the sixth passage 206 communicate with each other through the first small diameter portion 202.

For this reason, the clutch pressure acting as the hydraulic pressure in the seventh oil passage 56 is supplied to the hydraulic chamber 60 of the hydraulic clutch 58 via the fourth passage 172, the sixth passage 206, and the fifth passage 174, and the hydraulic clutch 58 is engaged. The driving force output from the automatic transmission 2 is connected, and the vehicle is in a state where it can move backward.

When the automatic transmission 2 is shifted to the neutral range N by the shift mechanism 122, the manual shift valve 126 is moved to the first small diameter portion of the spool valve body 132 as shown in FIG.
The first passage 166 communicates with the second oil passage 32 by 158, the second passage 168 communicates with the oil pan 29 side by the second small diameter portion 160, and the seventh oil passage 56 is closed by the fourth large diameter portion 154. ,
The third small diameter portion 162 connects the third passage 170 to the oil pan 29 side, and the fourth small diameter portion 164 connects the fourth passage 172 to the oil pan 29.
Communicate with the side.

As a result, the shift servo valve 106 is supplied with the line pressure to the first chamber 118 and discharges the line pressure of the second chamber 120, and the piston 112 moves the shift servo rod 114 in the direction of arrow A so that the shift fork 116 , The switching sleeve 86 is moved to the forward switching gear 90 side, the forward switching gear 90 is rotatably connected to the intermediate shaft 78, and is switched to the forward engagement state.

At this time, the hydraulic supply stop mechanism 176
The third passage 170 and the seventh passage 208 are communicated with each other by the first small diameter portion 204, but the manual shift valve 126 closes the seventh oil passage 56, and connects the third passage 170 and the fourth passage 172 to the oil pan. It communicates with the 29 side.

For this reason, since the clutch pressure is not supplied to the hydraulic chamber 60 of the hydraulic clutch 58, the hydraulic clutch 58 is not engaged, the driving force output from the automatic transmission 2 is cut off, and the vehicle cannot move backward.

When the automatic transmission 2 is shifted to the drive range D by the shift mechanism 122, the manual shift valve 126 is moved to the first small diameter portion 158 of the spool valve body 132 as shown in FIG.
The first passage 166 communicates with the second oil passage 32 by the
The second passage 168 communicates with the oil pan 29 side by the small diameter portion 160, and the third passage 170 is connected to the seventh oil passage by the third small diameter portion 162.
The fourth small-diameter portion 164 connects the fourth passage 172 to the oil pan 29 side.

As a result, the shift servo valve 106 is supplied with the line pressure to the first chamber 118 and discharges the line pressure of the second chamber 120, and the piston 112 moves the shift servo rod 114 in the direction of arrow A so that the shift fork 116 , The switching sleeve 86 is moved to the forward switching gear 90 side, the forward switching gear 90 is rotatably connected to the intermediate shaft 78, and is switched to the forward engagement state.

At this time, the hydraulic supply stop mechanism 176
The third passage 170 and the seventh passage 208 communicate with each other through the second small diameter portion 204.

For this reason, the clutch pressure acting as the hydraulic pressure in the seventh oil passage 56 is supplied to the hydraulic chamber 60 of the hydraulic clutch 58 via the third passage 170, the seventh passage 208, and the fifth passage 174, and the hydraulic clutch 58 is engaged. The driving force output from the automatic transmission 2 is connected, so that the vehicle can move forward.

When the automatic transmission 2 is shifted to the low range L by the shift mechanism 122, as shown in FIG. 7, the manual shift valve 126 causes the first passage 166 to move through the first oil passage 32 by the first small diameter portion 158 of the spool valve body 132. The second small diameter portion 160 communicates the second passage 168 to the oil pan 29 side, the third small diameter portion 162 communicates the third passage 170 to the seventh oil passage 56, and the fourth small diameter portion 164 4 Passage 172 to oil pan 29
Communicate with the side.

As a result, the shift servo valve 106 discharges the line pressure of the first chamber 118 and the line pressure of the second chamber 120, and the piston 112 moves the shift servo rod 114 in the direction of arrow A to shift the shift fork 116. , The switching sleeve 186 is moved to the forward switching gear 90 side, the forward switching gear 90 is rotatably connected to the intermediate shaft 78, and is switched to the forward engagement state.

At this time, the hydraulic supply stop mechanism 176
The third passage 170 and the seventh passage 208 communicate with each other through the second small diameter portion 204.

For this reason, the clutch pressure acting as the hydraulic pressure in the seventh oil passage 56 is supplied to the hydraulic chamber 60 of the hydraulic clutch 58 via the third passage 170, the seventh passage 208, and the fifth passage 174, and the hydraulic clutch 58 is engaged. The driving force output from the automatic transmission 2 is connected, and the vehicle is ready to move forward.

When the shift servo valve 106 of the automatic transmission 2 becomes inoperative due to some mechanical cause, the supply of clutch pressure to the hydraulic clutch 58 is stopped by the hydraulic supply stop mechanism 176 to engage the hydraulic clutch 58. To block.

For example, when the automatic transmission 2 is shifted to the reverse lens R by the shift mechanism 122, the manual shift valve 126 is connected to the first small diameter portion of the spool valve body 132 as shown in FIG.
158 connects the first passage 166 to the oil pan 29 side,
The small diameter portion 160 connects the second passage 168 to the second oil passage 32, the third small diameter portion 162 connects the third passage 170 to the oil pan 29, and the fourth small diameter portion 164 connects the fourth passage 172 to the seventh oil passage 32. It communicates with the oil passage 56.

At this time, as shown in FIG.
When the sixth piston 112 is in the inoperative state and the shift servo rod 114 cannot be moved in the direction of arrow B, the forward / reverse switching mechanism 80 is not switched to the reverse engagement state and is in the forward engagement state. When the shift servo valve 106 does not operate, the hydraulic supply stop mechanism 176 operates the second
The fourth passage 172 and the sixth passage 206 are closed by the large diameter portion 198, and the supply of the clutch pressure to the hydraulic chamber 60 of the hydraulic clutch 58 is stopped. Further, the hydraulic supply stop mechanism 176 is configured such that the second small diameter portion 204 of the spool valve element 182 allows the third passage 170 and the seventh passage 208
To guide the clutch pressure of the hydraulic chamber 60 to the oil pan 29 side.

Therefore, the engagement of the hydraulic clutch 58 is prevented, and the driving force output from the automatic transmission 2 is shut off, so that the vehicle cannot start.

Also, for example, when the automatic transmission 2 is shifted to the drive range D by the shift mechanism 122, as shown in FIG.
The manual shift valve 126 is connected to the first
The small diameter portion 158 communicates the first passage 166 with the second oil passage 32, the second small diameter portion 160 communicates the second passage 168 with the oil pan 29, and the third small diameter portion 162 forms the seventh passage of the third passage 170. The fourth passage 172 communicates with the oil pan 29 side, and the fourth passage 172 communicates with the oil pan 29 side.

At this time, as shown in FIG.
When the sixth piston 112 is in the inoperative state and the shift servo rod 114 cannot be moved in the direction of arrow A, the forward / reverse switching mechanism 80 is not switched to the forward engagement state and is in the reverse engagement state. When the shift servo valve 106 does not operate, the hydraulic supply stop mechanism 176 operates the second
The third passage 170 and the seventh passage 208 are closed by the large diameter portion 198, and the supply of the clutch pressure to the hydraulic chamber 60 of the hydraulic clutch 58 is stopped. Further, the hydraulic supply stop mechanism 176 is configured such that the first small diameter portion 202 of the spool valve element 182 allows the fourth passage 172 and the sixth passage 206
To guide the clutch pressure of the hydraulic chamber 60 to the oil pan 29 side.

Therefore, the engagement of the hydraulic clutch 58 is prevented, and the driving force output from the automatic transmission 2 is shut off, so that the vehicle cannot start.

As described above, when the shift servo valve 106 is not operated, the engagement of the hydraulic clutch 58 is prevented and the driving force output from the automatic transmission 2 is cut off, so that the vehicle cannot start. For this reason, safety can be ensured. Also, no special processing is required, the production is easy, and it is economically advantageous.

〔The invention's effect〕

Thus, according to the present invention, the automatic transmission switches the manual shift valve to the reverse lens or the drive range by the shift mechanism, and applies the line pressure as the hydraulic pressure to the first chamber or the second chamber of the shift servo valve. When the forward / reverse switching mechanism is switched from the forward engagement state to the reverse engagement state or from the reverse engagement state to the forward engagement state by supplying / discharging, the piston of the shift servo valve becomes inoperative and the shift servo rod is used. When the forward / reverse switching mechanism is not switched, the sixth to third hydraulic ports are connected to the fifth passage of the hydraulic clutch by the first to third large diameter portions and the first and second small diameter portions of the spool valve element of the hydraulic supply stop mechanism. -The seventh passage is switched and communicated with the third and fourth passages communicating with the manual shift valve to supply the hydraulic pressure to the hydraulic chamber of the hydraulic clutch. By discharging the hydraulic serving clutch pressure of the hydraulic chamber as well as stop, it can be shut off a driving force output from the automatic transmission and prevents the engagement of the hydraulic clutch.

Accordingly, when the forward / reverse switching mechanism is not switched due to the inactivation of the shift servo valve, the engagement of the hydraulic clutch is prevented, and the driving force output from the automatic transmission is cut off. Is unable to start. Therefore, safety when the shift servo valve is not operated can be ensured. Also, no special processing is required,
Easy to manufacture and economically advantageous.

[Brief description of the drawings]

1 to 9 show an embodiment of the present invention. FIG. 1 is an explanatory diagram of an operation when a shift servo valve is not operated in a reverse range, and FIG. 2 is an explanatory diagram of an operation when a shift servo valve is not operated in a drive range. FIG. 3 is an explanatory diagram of the operation of the shift servo valve in the parking range, FIG. 4 is an explanatory diagram of the operation of the shift servo valve in the reverse range, FIG. 5 is an explanatory diagram of the operation of the shift servo valve in the neutral range, and FIG. FIG. 7 is a diagram illustrating the operation of the shift servo valve in the drive range, FIG. 7 is a diagram illustrating the operation of the shift servo valve in the low range, FIG. 8 is a partial cross-sectional view illustrating the valve body, and FIG. FIG. In the figure, 2 is an automatic transmission, 4 is an input shaft, 6 is a driving pulley, 8 is an output shaft, 10 is a driven pulley, 12 is a belt, 28 is an oil pump, 58 is a hydraulic clutch, and 60 is a hydraulic chamber. , 76 is a final output shaft, 78 is an intermediate shaft, 80 is a forward / reverse switching mechanism, 106 is a shift servo valve, 126 is a manual shift valve, and 176 is a hydraulic supply stop mechanism.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48 F16D 25/00-39 / 00 B60K 41/00-41/28

Claims (1)

(57) [Claims] 1. An automatic transmission for automatically converting a driving force of an internal combustion engine according to a required gear ratio in accordance with a running state of a vehicle and extracting the driving force, a hydraulic clutch for interrupting the driving force output from the automatic transmission. A hydraulic clutch which is engaged and disengaged by supply and discharge of pressure is provided, and a forward / reverse switching mechanism for switching the forward / backward engagement state of the automatic transmission is provided. A line pressure as a hydraulic pressure is supplied to switch the forward / backward switching mechanism. A shift servo valve to be displaced is provided. The shift servo valve is provided with a piston slidably provided in a cylinder of a valve body. The piston defines a first chamber and a second chamber in the cylinder. A shift fork engaged with the switching sleeve of the forward / reverse switching mechanism on the other end of the shift servo rod. A manual shift valve which is switched by a shift mechanism of the automatic transmission to supply / discharge hydraulic pressure to / from the hydraulic clutch and supply / discharge hydraulic line pressure to / from the shift servo valve. The shift valve is provided with a spool valve body slidably connected at one end to an operating rod of the shift mechanism in a sliding hole of the valve body, and is provided on an inner peripheral surface of the sliding hole of the valve body of the manual shift valve. First to first
A seventh groove portion is provided, and the spool valve body is provided with first to fifth large-diameter portions slidably contacting the inner peripheral surface of the sliding hole.
First to fourth small-diameter portions are provided between the first to fifth large-diameter portions, and the first groove portion of the manual shift valve is provided to communicate with the first chamber of the shift servo valve through a first passage; A passage for supplying a hydraulic line pressure to the second groove portion of the manual shift valve; a third groove portion of the manual shift valve provided to communicate with a second chamber of the shift servo valve via a second passage; The fourth groove of the manual shift valve is provided in communication with the oil pan of the automatic transmission, the sixth groove of the manual shift valve is provided in communication with a passage for supplying clutch pressure as a hydraulic pressure, and the fifth groove of the manual shift valve and A seventh groove portion is provided to communicate with the third passage and the fourth passage, respectively, and the third passage and the fourth passage are communicated with the hydraulic chamber of the hydraulic clutch via the fifth passage. In order to prevent the engagement of the hydraulic clutch when the shift servo valve is inoperative, a hydraulic supply stop mechanism for stopping supply of hydraulic pressure to the hydraulic clutch is provided, and a valve body of the hydraulic supply stop mechanism is provided. A spool valve body provided integrally with the valve body of the shift servo valve and slidably housed in a slide hole of the valve body of the hydraulic supply stop mechanism is integrally formed with the shift servo rod of the shift servo valve. The first to sixth grooves are provided on the inner peripheral surface of the sliding hole of the valve body of the hydraulic supply stop mechanism, and slidably contact the inner peripheral surface of the sliding hole with the spool valve body of the hydraulic supply stop mechanism. First to third large-diameter portions are provided, and first and second small-diameter portions are respectively provided between the first to third large-diameter portions. A second groove portion of the hydraulic supply stop mechanism is provided in communication with a fifth passage of the hydraulic clutch through a sixth passage, and a third groove portion of the hydraulic supply stop mechanism is provided with a second groove portion of the manual shift valve. And a fourth groove portion of the hydraulic supply stop mechanism is provided in communication with a third passage of the manual shift valve, and a fifth groove portion of the hydraulic supply stop mechanism is provided with a seventh passage through the seventh passage. A fifth groove is provided in communication with the fifth passage, and a sixth groove of the hydraulic supply stop mechanism is provided in communication with the oil pan of the automatic transmission. The hydraulic supply stop mechanism switches the manual shift valve to a reverse range by the shift mechanism. Operate to supply hydraulic line pressure to the second chamber of the shift servo valve through the second passage and to apply hydraulic pressure to the first chamber of the shift servo valve through the first passage. When the forward / backward switching mechanism is switched from the forward engagement state to the reverse engagement state by discharging the line pressure, the piston of the shift servo valve becomes inactive and the forward / backward switching mechanism moves forward by the shift servo rod. When the engagement state is not switched to the reverse engagement state, the fourth passage and the sixth passage are formed by the second large diameter portion of the spool valve body of the hydraulic supply stop mechanism so as to prevent the engagement of the hydraulic clutch. To stop the supply of the hydraulic pressure to the hydraulic chamber of the hydraulic clutch, and to communicate the third passage and the seventh passage by the second small diameter portion to thereby provide a hydraulic barrel of the hydraulic chamber of the hydraulic clutch. The pressure is discharged to the oil pan via the third small diameter portion of the manual shift valve, and the hydraulic supply stop mechanism sets the manual shift valve to the drive range by the shift mechanism. Switching between forward and reverse by supplying the hydraulic pressure line pressure to the first chamber of the shift servo valve through the first passage and discharging the hydraulic pressure line pressure in the second chamber of the shift servo valve through the second passage. When switching the mechanism from the reverse engagement state to the forward engagement state, the piston of the shift servo valve becomes inoperative and the forward / reverse switching mechanism is switched from the reverse engagement state to the forward engagement state by the shift servo rod. If not, the third passage and the seventh passage are closed by the second large-diameter portion of the spool valve body of the hydraulic supply stop mechanism so as to prevent the engagement of the hydraulic clutch. The supply of the hydraulic pressure clutch pressure to the hydraulic chamber is stopped and the first small diameter portion connects the fourth passage and the sixth passage to reduce the hydraulic pressure of the hydraulic chamber of the hydraulic clutch. Safety device for an automatic transmission via a fourth small diameter portion of the serial manual shift valve, characterized in that discharging into the oil pan.