JP3035998B2 - Transmission shift control device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for a transmission, and in particular, converts a driving force of an internal combustion engine into a required speed ratio in accordance with a running state of a vehicle and extracts the driving force. The present invention relates to a shift control device for a transmission having a hydraulic clutch that is engaged and disengaged by supplying and discharging hydraulic pressure in order to intermittently output driving force.

2. Description of the Related Art In a vehicle such as an automobile, a transmission is provided in order to appropriately extract a driving force generated by an internal combustion engine according to a 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 of the internal combustion engine automatically to the required gear ratio according to the traveling state. In addition, there is an automatic, that is, a continuously variable transmission or the like that converts and takes out in a stepless manner.

As a transmission, there is a transmission disclosed in Japanese Patent Application Laid-Open No. 62-196443. The shift control method for a vehicle transmission disclosed in this publication is characterized in that the sleeve of the synchronous meshing device is used for the stepped transmission within a predetermined time after the shift lever is operated from the non-travel position to the travel position. When the gear does not reach the position indicating the establishment of the gear, the torque of a predetermined magnitude is transmitted for a short time through the automatic clutch, and the transmission between the synchronizing ring of the synchromesh and the output gear of the stepped transmission is performed. A relative rotational force is applied in between to enable relative rotation of the synchronous ring and the output gear, which have been unable to rotate, thereby eliminating the inability to switch gears due to poor relative rotation.

Also, there is one disclosed in JP-A-63-1840. In the vehicular transmission equipped with the auxiliary transmission disclosed in this publication, the sleeve does not reach the first position or the second position even when the shift operation lever is switched to the forward or reverse range when the vehicle is stopped. Occasionally, the rotation of the rotating member is allowed by a predetermined amount, and the forward gear or the reverse gear is rotated relative to the sleeve by a predetermined amount, so that interference between the sleeve and the forward gear or the reverse gear is immediately eliminated, and the gear noise is reduced. And the gear stage of the auxiliary transmission is more reliably established.

Further, a shift mechanism of the continuously variable transmission is disclosed in
JP-A-144338, JP-A-57-144339, JP-A-58-144339
156754, JP-A-60-159452, JP-A-60-15
Most of the publications such as 9453 employ a mechanical shift mechanism. Although this mechanical shift mechanism is widely used, the use of a hydraulic shift mechanism has an advantage that a shift operation can be performed smoothly as compared with a mechanical shift mechanism, and has recently become popular.

Further, as shown in FIG. 14, the clutch pressure and the line pressure are respectively supplied to the manual shift valve 472 of the hydraulic control circuit 404 of the hydraulic shift mechanism, and the clutch pressure and the line pressure are also supplied to the shift servo valve 480. And pressure are supplied respectively.

[Problems to be Solved by the Invention] By the way, in the conventional transmission shift control device,
In some transmissions, for example, a forward / reverse switching mechanism that switches a forward / backward engagement state of a transmission is mechanically switched 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, a shift mechanism operates a manual shift valve to supply / discharge hydraulic pressure to / from a shift servo valve, and the shift servo valve switches a forward / backward switching mechanism that switches, for example, a forward / backward engagement state of the transmission. is there. 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, a chamfer portion where the gear and the sleeve mesh with each other at the time of the shift operation comes into contact with each other substantially at the apex, and a stop phenomenon of poor engagement may occur.

Although the same stop phenomenon occurs in the mechanical shift mechanism, since the select lever and the shift portion are directly linked, when the stop phenomenon of poor engagement occurs, the select lever is instructed. The shift operation is performed again by operating the select lever again without confirming the engagement failure without operating to the position.

However, in the case of a hydraulic shift mechanism, a shift error,
That is, when a stop phenomenon due to poor engagement occurs, the select lever operates to the designated position, and the D range or R
Despite instructing the range, the driving force is not transmitted due to the occurrence of the stop phenomenon, and there is a disadvantage that the vehicle cannot start.

It is also conceivable that when a stop phenomenon occurs, either the gear or the sleeve is rotated to eliminate the stop phenomenon and complete the shift operation, but at the time of the stop phenomenon, the clutch is connected to rotate the gear. Then, there is a disadvantage that a ratchet sound (for example, a rattling sound) is generated at the chamfered portion and at least one of the gear and the sleeve may be damaged.

[Object of the Invention] Accordingly, an object of the present invention is to provide a forward / reverse switching mechanism that switches the forward / reverse engagement state of a transmission by a forward gear, a reverse gear, and a switching member between the two gears in order to eliminate the above-described disadvantage. A shift servo valve is provided which engages a shift fork of a shift servo rod with a switching member of the forward / reverse switching mechanism, switches the forward / reverse switching mechanism to supply / discharge hydraulic pressure, and uses clutch pressure as a servo cylinder pressure. A check switch for checking the position of the shift servo valve is provided at the end of the shift servo rod of the valve, and the engagement state between either the forward gear or the reverse gear of the forward / reverse switching mechanism and the switching member is engaged by the check switch. When it is confirmed that the clutch is defective, the clutch pressure is temporarily reduced to temporarily reduce the servo cylinder pressure of the shift servo valve, and the forward / backward switching is performed. Rotating at least one of the forward gear or the reverse gear of the mechanism and the switching member,
Then, the clutch pressure is increased again to increase the servo cylinder pressure of the shift servo valve, and in order to eliminate a defective engagement state between the gear and either the forward gear or the reverse gear of the forward / reverse switching mechanism and the switching member. By configuring,
It is an object of the present invention to realize a shift control device for a transmission that can eliminate a poor engagement between one of a forward gear and a reverse gear and a switching member and can reliably perform a shift operation.

Means for Solving the Problems In order to achieve this object, the present invention converts the driving force of the internal combustion engine into a required gear ratio in accordance with the running state of the vehicle, takes out the driving force, and intermittently outputs the driving force. A transmission having a hydraulic clutch engaged and disengaged by supply and discharge of hydraulic pressure, a forward / reverse switching mechanism for switching the forward / reverse engagement state of the transmission by a forward gear, a reverse gear, and a switching member between the two gears. The shift fork of the shift servo rod is engaged with the switching member of the forward / reverse switching mechanism, and the forward / backward switching mechanism is switched to provide a shift servo valve that uses clutch pressure as a servo cylinder pressure to supply and discharge hydraulic pressure. A check switch for checking the position of the shift servo valve is provided at the end of the shift servo rod of the servo valve. When the engagement state between one of the gears and the switching member is confirmed to be poorly engaged by the confirmation switch, the clutch pressure is temporarily reduced to temporarily reduce the servo cylinder pressure of the shift servo valve, At least one of the forward gear or the reverse gear of the forward / reverse switching mechanism and the switching member is rotated, and then the clutch pressure is increased again to increase the servo cylinder pressure of the shift servo valve. The present invention is characterized in that it is configured to eliminate a poor engagement state between one of the forward gear and the reverse gear of the forward switching mechanism and the switching member.

[Operation] With the configuration described above, when either one of the forward gear and the reverse gear is not properly engaged with the switching member, the clutch pressure is temporarily reduced to reduce the servo cylinder of the shift servo valve. The pressure is once reduced, and at least one of the forward gear or the reverse gear of the forward / reverse switching mechanism and at least one of the switching members is rotated. Then, the clutch pressure is increased again to increase the servo cylinder of the shift servo valve. By increasing the pressure, poor engagement between one of the forward gear and the reverse gear of the forward / reverse switching mechanism and the switching member is eliminated, and the shift operation is reliably performed.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

1 to 13 show an embodiment of the present invention. In FIG. 3, reference numeral 2 denotes a vehicle transmission, for example, a continuously variable transmission,
Reference numeral 4 denotes a hydraulic control circuit of the shift control device. The continuously variable transmission 2 converts the power of an internal combustion engine (not shown) as required by continuously changing the speed ratio, and takes out the power. The primary sheave 6 operated by the hydraulic pressure of the hydraulic control circuit 4 is used. And secondary sheave 8 and clutch, ie hydraulic clutch 10
And

The hydraulic control circuit 4 is provided with an oil pump 12. The oil pump 12 sucks oil in an oil pan (not shown), sends the oil to a line pressure passage 14, and supplies the oil to the secondary sheave 8.

An oil strainer 16 for filtering oil is provided between the oil pan and the oil pump 12.

A first line pressure control valve 20 is connected to the line pressure passage 14 via a first oil passage 18, a second line pressure control valve 24 is connected via a second oil passage 22, and a third oil passage The ratio pressure control valve 28 is communicated via 26, the clutch pressure control valve 32 is communicated via a fourth oil passage 30, the solenoid regulator valve 36 is communicated via a fifth oil passage 34, and the sixth oil passage. A relief valve 40 is connected via a line 38.

The first line pressure control valve 20 and the second line pressure control valve 24 are connected by a seventh oil passage 42.

An eighth oil passage 46 provided with a line solenoid 44 is connected to the first line pressure control valve 20.

The ratio pressure control valve 28 has a ratio solenoid.
A ninth oil passage 50 provided with 48 is connected.

The eighth oil passage 46 and the ninth oil passage 50 are connected at a connection portion 52.

The ratio pressure control valve 28 communicates with the primary sheave 6 via a ratio pressure passage 54. In the middle of the ratio pressure passage 54, a tenth oil passage communicating with a cooling control valve 56 is provided.
58 is connected.

An oil cooler 62 is connected to the cooling control valve 56 via an eleventh oil passage 60, and is connected to the clutch pressure control valve 32 via a clutch pressure passage 64.
Is connected to the hydraulic clutch 10. In the middle of the clutch pressure passage 64, a manual shift valve 72 is connected via twelfth and thirteenth oil passages 68 and 70.

A clutch solenoid 76 is connected to the clutch pressure control valve 32 via a fourteenth oil path 74.

The hydraulic clutch 10 is connected to a shift servo valve 80 via a fifteenth oil passage 78.

This shift servo valve 80 includes a servo cylinder 82,
Servo piston 84 that moves in this servo cylinder 82
And a shift servo rod fixed to the servo piston 84
A shift fork 88 fixed to the shift servo rod 86 and operating a forward / reverse switching mechanism 116 to be described later is provided.

Further, the shift servo valve 80 and the manual shift valve 72 are connected to the sixteenth
It is communicated with the oil passage 92.

An eighteenth oil passage 94 communicating with a clutch solenoid 76 is connected to a connection portion 56 between the ninth oil passage 50 and the tenth oil passage 54.

The eighteenth oil passage 94 has a
The 19th oil passage 96, the 20th oil passages 98-1 and 98-2 communicating with the solenoid regulator valve 36, the 21st oil passage 100 communicating with the first line pressure control valve 20, and the clutch pressure control valve 32 And the 22nd oil passages 102-1 and 102-2.

Further, a loop pressure passage 104 is connected between the oil pump 12 and the second line pressure control valve 24. A lube pressure regulator valve 106 is provided in the middle of the lube pressure passage 104. The lube pressure passage 104 is connected to a 23rd oil passage 108 for supplying oil for lubrication and cooling of each part, and the clutch pressure control valve 32 is connected via a 24th oil passage 110 to the 25th oil passage. The cooling control valve 60 is connected via the line 112.

Further, the line solenoid 44, the ratio solenoid 4
8. The clutch solenoid 76 is controlled by the control means (ECU) (not shown) of the continuously variable transmission 2 by communicating with the control means (not shown).

Further, a final output shaft (not shown) of the hydraulic clutch 10 is connected to a drive wheel (not shown) via an intermediate shaft 114 as shown in FIG. A forward / reverse switching mechanism that switches the forward / backward engaged state between the final output shaft and the intermediate shaft 114
116 are provided. The forward / reverse switching mechanism 116 includes a forward gear 118, a reverse gear 120, and a switching sleeve 122 as a switching member.
And The forward gear 118 includes a forward output gear fixed to the final output shaft, and a forward switching gear 126 rotatably supported by the intermediate shaft 114 so as to mesh with the forward output gear 124.

The reverse gear 120 includes a reverse output gear fixed to the final output shaft, a reverse switching gear 130 rotatably supported on the intermediate shaft 114, a reverse output gear 128, and a reverse switching gear 130. And an idler gear (not shown) for meshing and connecting the gears.

The switching sleeve 122 is mounted on the intermediate shaft 114 so as to be axially movable and non-rotatable, so that one of the forward switching gear 126 and the reverse switching gear 130 cannot be rotated on the intermediate shaft 114 by axial movement. To switch the forward / backward engagement state.

The control means includes a carburetor throttle opening, a carburetor idle position, an accelerator pedal signal, a brake signal, a power mode option signal, and a shift lever position in accordance with the clutch pressure, the drive side rotation speed, and the driven side rotation speed signal. And other various signals.

The control means controls the belt ratio of the continuously variable transmission 2 and the engaged / disengaged state of the clutch in various control modes according to various input signals.

As shown in FIGS. 6 to 9, the shift servo valve 80 for supplying and discharging the hydraulic pressure so as to perform the switching operation of the forward / reverse switching mechanism 116 includes a servo piston 84 slidably inserted into a servo cylinder 82 of a valve body 132. Provided by connecting one end side of the shift servo rod 86 to this servo piston 84,
A shift fork 88 engaged with the switching sleeve 122 of the forward / reverse switching mechanism 116 is fixedly mounted on the shift servo rod 86.

When the hydraulic pressure is supplied to the first chamber 134 defined by the servo piston 84 in the servo cylinder 82 and the hydraulic pressure in the second chamber 136 is discharged, the shift servo valve 80
The servo piston 84 moves the shift servo rod 86 in the direction of arrow A in FIGS. 5 and 8 to move the switching sleeve 122 toward the forward switching gear 126 by the shift fork 88,
The forward switching gear 126 is rotatably connected to the intermediate shaft 114, and is switched to the forward engagement state. On the other hand, shift servo valve 80
The hydraulic pressure is supplied to the second chamber 136 defined by the servo piston 84 in the servo cylinder 82 and the first
When the oil pressure in the chamber 134 is discharged, the servo piston 84 moves the shift servo rod 86 in the direction of arrow B in FIGS. 5 and 7, and moves the switching sleeve 122 toward the reversing switching gear 130 by the shift fork 88. The reversing switching gear 130 is non-rotatably connected to the intermediate shaft 114 to switch to the retreat engagement state.

In order to supply / discharge hydraulic pressure to / from the hydraulic clutch 10 and supply / discharge hydraulic pressure to / from the shift servo valve 80, the continuously variable transmission 2
The manual shift valve 72 that is switched by the operating rod 140 of the shift mechanism 138 is provided.

As shown in FIGS. 6 to 9, the manual shift valve 72 has a spool valve element 146 in a sliding hole 144 of the valve body 142.
Is slidably mounted. The valve body 142 is provided with annular first groove portions 148 to seventh groove portions 160 on the inner peripheral surface of the sliding hole 144. The spool valve 146 has one end connected to the operating rod 140 of the shift mechanism 138, and the first large diameter portion 162 to the fifth large diameter portion slidably contacting the inner peripheral surface of the sliding hole 144.
170 and the first to fifth large diameter portions 162 to 17
A first small diameter portion 172 to a fourth small diameter portion 178 are provided between 0.

The first groove portion 148 provided in the valve body 142 of the manual shift valve 72 communicates with the first passage 180.
The first passage 180 is provided with a first passage of the shift servo valve 80.
It is in communication with the chamber 134. The manual shift valve 7
The second groove 150 provided in the second valve body 142 is
A line pressure, which is a hydraulic pressure, is connected to the oil passage 70 and acts on the hydraulic clutch 10. The manual shift valve 72
The third groove 152 provided in the valve body 142 of the second passage 18
Communicated with 2. The second passage 182 communicates with the second chamber 136 of the shift servo valve 80. The fourth groove 1 provided in the valve body 142 of the manual shift valve 72
54 is connected to an oil pan (not shown).

Also, the valve body 142 of the manual shift valve 72
The fifth groove portion 156 provided at the bottom is communicated with the seventeenth oil passage 92. The sixth groove 158 of the manual shift valve 72
Is connected to the twelfth oil passage 68, and is supplied with a hydraulic pressure acting on the hydraulic clutch 10. The seventh groove 160 of the manual shift valve 72 communicates with the sixteenth oil passage 90. The hydraulic clutch 10 is connected to the sixteenth and seventeenth oil passages 9.
The clutch pressure, which is a hydraulic pressure, is supplied / discharged via the fifteenth oil passage 78 by means of 0 and 92. A pressure sensor 184 for detecting a clutch pressure is provided in the middle of the fifteenth oil passage 78.

In order to prevent the engagement of the hydraulic clutch 10 when the shift servo valve 80 is not operated, a hydraulic supply stop mechanism 18 for stopping supply of hydraulic pressure to the hydraulic clutch 10 is provided.
6 is provided.

The hydraulic supply stop mechanism 186 is provided with the shift servo valve 80.
Are provided integrally. That is, the hydraulic supply stop mechanism 186 has a spool valve body 192 slidably mounted in a slide hole 190 of a valve body 188 provided integrally with the valve body 132 of the shift servo valve 80. This spool valve element 1
Reference numeral 92 is formed integrally with the shift servo rod 86. On the inner peripheral surface of the sliding hole 190 of the valve body 188,
An annular first groove portion 194 to a sixth groove portion 204 are provided. The spool valve body 192 slides in contact with the inner peripheral surface of the sliding hole 190.
A large diameter portion 206 to a third large diameter portion 210 are provided, and a first small diameter portion 212 and a second small diameter portion 214 are provided between the first to third large diameter portions 206 to 210.

The first groove 194 provided in the valve body 188 of the hydraulic supply stop mechanism 186 is connected to an oil pan (not shown). The second groove 196 of the hydraulic supply stop mechanism 186 is provided in the third passage
216 communicates with the fifteenth oil passage 78. The third groove portion 198 of the hydraulic pressure supply stop mechanism 186 communicates with the sixteenth oil passage 90. The fourth groove 200 of the hydraulic supply stop mechanism 186
Is connected to the seventeenth oil passage 92. The fifth groove portion 202 of the hydraulic pressure supply stop mechanism 186 is connected to the first passage by the fourth passage 218.
It is connected to 5 oil passage 78. The sixth groove 204 of the hydraulic supply stop mechanism 186 is connected to an oil pan (not shown).

The hydraulic control circuit 4 of the continuously variable transmission 2 has, for example, two first and second line pressure control valves 20 and 24.

The shift servo valve 80 for switching the forward / reverse switching mechanism 116 of the continuously variable transmission 2 to supply and discharge the hydraulic pressure by using the clutch pressure as the servo cylinder pressure is provided. A confirmation switch 220 for confirming the position of the shift servo valve 80 is provided in the section. The forward gear 118 of the forward / reverse switching mechanism 116
Alternatively, when the engagement state between any one of the reversing gears 120 and the switching sleeve 122 is confirmed to be poorly engaged by the confirmation switch 220, the clutch pressure is temporarily reduced and the servo of the shift servo valve 80 is controlled. The cylinder pressure is temporarily reduced, and at least one of the forward gear 118 or the reverse gear 120 of the forward / reverse switching mechanism 116 and at least one of the switching sleeve 122 is rotated, and then the clutch pressure is increased again. By increasing the servo cylinder pressure of the shift servo valve 80, either the forward gear 118 or the reverse gear 120 of the forward / reverse switching mechanism 116 and the switching sleeve 122
It is configured to eliminate the defect of the engagement state with the.

More specifically, as shown in FIG. 2, one of the forward gear 118 and the reverse gear 120, for example, the forward gear 118
And the leading end engaging portion 122a of the switching sleeve 122
When the end of the shift servo valve 8 is confirmed by the confirmation switch 220 comprising a potentiometer switch, etc.
If the 0 shift servo rod 86 is not in the correct position, the clutch pressure is temporarily reduced and the shift servo valve 80
, The at least one of the forward gear 118 and the switching sleeve 122 is rotated, and then the clutch pressure is increased again to increase the servo cylinder pressure. Gear 118
Alternatively, the configuration is such that any one of the gears of the reversing gear 120 and the switching sleeve 122 are eliminated from a defective engagement state.

The shift servo rod 86 of the shift servo valve 80
Are the correct positions as shown in FIGS. 10-13.
The shift servo rod 86 is in the A position in the range, and the shift servo rod 86 is in the B position in the P and R ranges.

 Next, the operation will be described.

The driving force of the internal combustion engine mounted on the vehicle is controlled by the continuously variable transmission 2
Is converted into the desired torque and rotation speed by
The drive wheels (not shown) are driven.

In such a continuously variable transmission 2, when the continuously variable transmission 2 is shifted to the parking range P by the shift mechanism 138, as shown in FIG.
The first small diameter portion 172 of the spool valve element 146 communicates the first passage 180 with the oil pan (not shown), the second small diameter portion 174 communicates the second passage 182 with the thirteenth oil passage 70, and the fourth large diameter portion. The twelfth oil passage 68 is closed by the 168 and the fifth large diameter portion 170, the seventeenth oil passage 92 is connected to the oil pan side by the third small diameter portion 176, and the sixteenth oil passage is closed by the outer end of the fifth large diameter portion 170. The road 90 communicates with the oil pan.

As a result, the shift servo valve 80 releases the clutch pressure in the first chamber 134 and supplies the clutch pressure to the second chamber 136.
86 is moved in the direction of arrow B, the shift sleeve 122 is moved by the shift fork 88 to the reversing switching gear 130 side, and the reversing switching gear 130 is non-rotatably connected to the intermediate shaft 114 to switch to the retreat engagement state. .

At this time, the hydraulic supply stop mechanism 186
The 16th oil passage 90 and the third passage 216 communicate with each other through the first small-diameter portion 212, but the manual shift valve 72 is connected to the twelfth oil passage 68.
And the seventeenth oil passage 92 and the sixteenth oil passage 90 communicate with the oil pan side.

For this reason, since the clutch pressure is not supplied to the hydraulic clutch 10, the hydraulic clutch 10 is not engaged, the driving force output from the continuously variable transmission 2 is cut off, and the vehicle is unable to retreat.

When the continuously variable transmission 2 is shifted to the reverse range R by the shift mechanism 138, the manual shift valve 72 moves the first passage 180 through the first small diameter portion 172 of the spool valve body 146 to the oil pan side as shown in FIG. 2nd small diameter part 1
The second passage 182 communicates with the thirteenth oil passage 70 through 74, the seventeenth oil passage 92 communicates with the oil pan side through the third small diameter portion 176, and the sixteenth oil passage 90 communicates with the twelfth oil passage 90 through the fourth small diameter portion 178. It communicates with the oil passage 68.

As a result, the shift servo valve 80 releases the clutch pressure in the first chamber 134 and supplies the clutch pressure to the second chamber 136.
86 is moved in the direction of arrow B, the shift sleeve 122 is moved by the shift fork 88 to the reversing switching gear 130 side, and the reversing switching gear 130 is non-rotatably connected to the intermediate shaft 114 to switch to the retreat engagement state. .

At this time, the hydraulic supply stop mechanism 186
The sixteenth oil passage 90 and the third passage 216 are communicated by the first small diameter portion 212.

Therefore, the clutch pressure acting as the hydraulic pressure in the twelfth oil passage 68 is increased via the sixteenth oil passage 90, the third passage 216, and the fifteenth oil passage 78.
0, the hydraulic clutch 10 is engaged, the driving force output from the continuously variable transmission 2 is connected, and the vehicle is in a state where the vehicle can retreat.

When the continuously variable transmission 2 is shifted to the drive range D by the shift mechanism 138, the manual shift valve 72 causes the first passage 180 to move through the thirteenth oil through the first small diameter portion 172 of the spool valve body 146 as shown in FIG. The second small diameter portion 174
Communicates the second passage 182 to the oil pan side, connects the seventeenth oil passage 92 to the twelfth oil passage 68 by the third small diameter portion 176, and connects the sixteenth oil passage 90 to the oil pan side by the fourth small diameter portion 178. Communicate.

As a result, the shift servo valve 80 supplies the clutch pressure to the first chamber 134 and discharges the clutch pressure from the second chamber 136.
The switch sleeve 122 is moved to the forward switching gear 130 side by the shift fork 88 by moving the 86 in the direction of arrow A, and the forward switching gear 130 is rotatably connected to the intermediate shaft 114 to switch to the forward engaged state.

At this time, the hydraulic supply stop mechanism 186
The seventeenth oil passage 92 and the fourth passage 218 communicate with each other through the second small diameter portion 214.

For this reason, the clutch pressure acting as the hydraulic pressure in the twelfth oil passage 68 is increased via the seventeenth oil passage 92, the fourth passage 218, and the fifteenth oil passage 78.
0, the hydraulic clutch 10 is engaged, the driving force output from the continuously variable transmission 2 is connected, and the vehicle can move forward.

When the continuously variable transmission 2 is shifted to the low range L by the shift mechanism 138, the manual shift valve 72 causes the first passage 180 to move through the thirteenth oil passage by the first small diameter portion 172 of the spool valve body 146 as shown in FIG. 70, the second passage 182 is communicated to the oil pan side by the second small diameter portion 174, and the third small diameter portion 176
The 17th oil passage 92 communicates with the twelfth oil passage 68, and the fourth small diameter portion 17
8 connects the 16th oil passage 90 to the oil pan side.

As a result, the shift servo valve 80 releases the clutch pressure to the first chamber 134 and the clutch pressure to the second chamber 136.
The switch sleeve 122 is moved to the forward switching gear 130 side by the shift fork 88 by moving the 86 in the direction of arrow A, and the forward switching gear 130 is rotatably connected to the intermediate shaft 114 to switch to the forward engaged state.

At this time, the hydraulic supply stop mechanism 186
The seventeenth oil passage 92 and the fourth passage 218 communicate with each other through the second small diameter portion 214.

For this reason, the clutch pressure acting as the hydraulic pressure in the twelfth oil passage 68 is increased via the seventeenth oil passage 92, the fourth passage 218, and the fifteenth oil passage 78.
0, the hydraulic clutch 10 is engaged, the driving force output from the continuously variable transmission 2 is connected, and the vehicle can move forward.

When the continuously variable transmission 2 is shifted by the shift mechanism 138, as shown in FIG.
The distal end engaging portion 118a of the switching sleeve 122 and the distal end engaging portion
If the respective ends of the shift servo valve 2a come into contact with each other and stop in a substantially straight line, resulting in poor engagement, the clutch pressure is temporarily reduced to temporarily reduce the servo cylinder pressure of the shift servo valve 80. Then, the clutch pressure is increased again to increase the servo cylinder pressure, and the poor engagement state of the forward / reverse switching mechanism 116 is eliminated.

In other words, according to the shift control flowchart of FIG. 1, the program of the shift control flowchart is started (300) by driving the internal combustion engine (not shown) of the vehicle.

Then, it is determined whether or not the shift operation is a shift operation to the drive range D (302). This decision (3
If 02) is NO, the process shifts to a shift control flowchart (not shown) for the R, N, and P ranges other than the D range (304), and if the determination (302) is YES, the clutch The pressure is increased (306). After increasing the clutch pressure, the servo cylinder pressure is also increased (308).

During the shift operation to the drive range D, the position of the shift servo rod 86 of the shift servo valve 80 is confirmed by the confirmation switch 220, and it is determined by the confirmation switch 220 whether the position of the shift servo rod 86 is correct (310). ).

If this determination (310) is YES, return (324)
If the judgment (310) is YES, that is, if the position of the shift servo rod 86 is not at the correct position,
The clutch pressure is temporarily reduced (312), and the servo cylinder pressure of the shift servo valve 80 is temporarily reduced (314). Thereafter, the clutch pressure is increased again (316), the servo cylinder pressure of the shift servo valve 80 is increased (318), and the engagement between the forward gear 118 and the switching sleeve 122 is ensured. The defective state of engagement with the sleeve 122 is eliminated.

Then, the position of the shift servo rod 86 of the shift servo valve 80 is confirmed by the confirmation switch 220, and the confirmation switch 220 determines whether or not the position of the shift servo rod 86 is correct (320).

If this determination (320) is NO, the shift routine (3
After 22), the process is shifted to the reduction of the clutch pressure (312), and if the judgment (320) is YES, the process is shifted to the return (324).

With this, when the position of the shift servo rod 86 is not at the correct position, the clutch pressure is temporarily reduced to temporarily reduce the servo cylinder pressure of the shift servo valve 80,
At least one of the forward gear 118 and the switching sleeve 122 is slightly rotated, and then the clutch pressure is increased again to increase the servo cylinder pressure of the shift servo valve 80, thereby engaging the forward gear 118 with the switching sleeve 122. The state can be assured, the forward gear 118 and the switching sleeve 1
It is possible to eliminate the failure of the engagement state with the gear 22 and to prevent the vehicle from starting at the time of the shift operation, generate a ratchet sound (for example, a rattling sound) at the chamfer portion, and at least make the forward gear 118, the reverse gear 120, or the switching sleeve 122 The disadvantage that one of them is damaged can be avoided, which is practically advantageous.

In addition, the hydraulic control circuit 4 is only slightly changed, and the forward gear 118, the reverse gear 120, and the switching sleeve 122 do not need to be specially processed in production, so that the configuration can be easily maintained and the production is easy. Therefore, the cost can be reduced, and it is economically advantageous.

[Effects of the Invention] As described above in detail, according to the present invention, there is provided a forward / reverse switching mechanism for switching the forward / reverse engagement state of the transmission by a forward gear, a reverse gear, and a switching member between the two gears. The shift fork of the shift servo rod is engaged with the switching member of the switching mechanism, the forward / backward switching mechanism is switched, and a shift servo valve is provided for changing the clutch pressure to the servo cylinder pressure to supply and discharge the hydraulic pressure. A confirmation switch for confirming the position of the shift servo valve is provided at the end of the servo rod, and the engagement state between one of the forward gear and the reverse gear of the forward / reverse switching mechanism and the switching member is poorly engaged by the confirmation switch. When it is confirmed that the clutch pressure is once decreased, the servo cylinder pressure of the shift servo valve is temporarily decreased, and the forward gear of the forward / reverse switching mechanism is shifted. At least one of the first gear and the reverse gear and the switching member are rotated, and then the clutch pressure is increased again to increase the servo cylinder pressure of the shift servo valve and the forward gear of the forward / reverse switching mechanism. Or, since it is configured to eliminate the failure of the engagement state between one of the reverse gears and the switching member, if the position of the shift servo rod is not at the correct position, the servo cylinder pressure is reduced once, and then By increasing the servo cylinder pressure, the engagement state between the forward gear or the reverse gear and the switching sleeve can be confirmed, the poor engagement state of the forward / reverse switching mechanism can be eliminated, and Inability to start or ratchet noise at the chamfer area, and damage to at least one of the starting gear, reverse gear and switching sleeve. Avoid to give, which is advantageous in practical use. Further, since there is no need to specially process the forward gear, the reverse gear, and the switching sleeve in manufacturing, the configuration can be maintained simply, the manufacturing is easy, the cost can be reduced, and the cost can be reduced. It is advantageous.

[Brief description of the drawings]

1 to 13 show an embodiment of the present invention, FIG. 1 is a flowchart for shift control of a transmission, FIG. 2 is an enlarged view of a main part showing a state in which engagement of a sleeve and a gear is incorrectly performed, and FIG. FIG. 4 is a plan view of a shift servo valve, FIG. 5 is a front view of the shift servo valve, FIG.
FIG. 7 is a schematic diagram showing the operation of the shift servo valve in the P range, FIG. 7 is a schematic diagram showing the operation of the shift servo valve in the R range, and FIG. 8 is the operation of the shift servo valve in the D range. FIG. 9 is a schematic diagram showing the operation of the shift servo valve in the L range, FIG. 10 is a schematic diagram showing the shift servo valve position in the P range, and FIG. 11 is a diagram in the R range. FIG. 12 is a schematic diagram showing shift servo valve positions in the case of the D range, and FIG. 13 is a schematic diagram showing shift servo valve positions in the case of the L range. FIG. 14 is a schematic diagram of a hydraulic control circuit of a transmission showing the prior art of the present invention. In the figure, 2 is a continuously variable transmission, 4 is a hydraulic control circuit, 6 is a primary sheave, 8 is a secondary sheave, 10 is a hydraulic clutch, 14 is a line pressure passage, 20 is a first line pressure control valve,
24 is the second line pressure control valve, 28 is the ratio pressure control valve, 32 is the clutch pressure control valve, 54 is the ratio pressure passage, 56 is the cooling control valve, 64 is the clutch pressure passage, 72 is the manual shift valve, and 80 is the shift Servo valve, 86 is shift servo rod, 88 is shift fork, 114 is intermediate shaft, 116 is forward / reverse switching mechanism, 118 is forward gear, 120 is reverse gear, 122 is switching sleeve, 138 is shift mechanism, 186 is hydraulic pressure supply Stop mechanism, 22
0 is a confirmation switch.

Claims (1)

(57) [Claims] 1. A transmission having a hydraulic clutch that is engaged and disengaged by supplying and discharging hydraulic pressure to convert and extract a driving force of an internal combustion engine to a required gear ratio in accordance with a traveling state of a vehicle and to intermittently output the driving force. A forward / backward switching mechanism for switching the forward / backward engaged state of the transmission by a forward gear, a reverse gear, and a switching member between the two gears, and a shift fork of a shift servo rod is attached to the switching member of the forward / backward switching mechanism. And a shift servo valve that uses the clutch pressure as the servo cylinder pressure to supply and discharge the hydraulic pressure by switching the forward / reverse switching mechanism and checking the position of the shift servo valve at the end of the shift servo rod of the shift servo valve. A confirmation switch is provided, and the engagement state between one of the forward gear and the reverse gear of the forward / reverse switching mechanism and the switching member is determined by the confirmation switch. When it is confirmed that the engagement is poor, the clutch pressure of the shift servo valve is temporarily reduced by temporarily lowering the clutch pressure, and the gear of either the forward gear or the reverse gear of the forward / reverse switching mechanism is reduced. Rotate at least one of the switching members, and then
The clutch pressure is increased again to increase the servo cylinder pressure of the shift servo valve, and the failure of the engagement state between either the forward gear or the reverse gear of the forward / reverse switching mechanism and the switching member is eliminated. A shift control device for a transmission.