JPS6120747B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a speed change control device for an automatic transmission, which is used in a vehicle such as an automobile, and includes a hydraulic torque converter and a gear transmission. As is well known, a hydraulic automatic transmission is configured to automatically change gears in relation to vehicle speed and throttle opening when a speed selection valve is in an automatic change range. The vehicle speed is detected by the governor valve as an oil pressure signal proportional to the vehicle speed, while the throttle opening is detected by the throttle valve as an oil pressure signal proportional thereto. These two hydraulic signals are respectively guided to one or more shift valves, and by opening and closing the shift valves, a brake or clutch attached to the gear transmission is engaged to perform gear shifting. In such a hydraulic automatic transmission, gear changes are normally performed on a shift line related to throttle opening and vehicle speed, and this shift line has a characteristic such that the larger the throttle opening, the faster the vehicle speed is shifted.
In order to stabilize the operation of the automatic transmission near the shift point, a hysteresis effect is added to the shift characteristics, so that in the case of a downshift, if the throttle opening is the same, the vehicle speed will shift lower than the vehicle speed during an upshift. The shift is configured to take place. Furthermore, in order to prevent shock during gear shifting, the hysteresis width at high throttle openings is made as large as possible, and in order to widen the usable range of high gears, the hysteresis width at low throttle openings is made as small as possible. is required to do so. Conventionally, when the hysteresis width is small, a shift shock tends to occur when the hysteresis width is small.
In particular, when driving on a road surface with steep ups and downs in overdrive (4th gear) or 3rd gear, there was a problem in that the gear shifting was constant. In order to solve this problem, it is necessary to change the hysteresis width as much as possible, and in order to satisfy this, a method of providing a separate control valve has been devised, but a separate control valve is provided in the conventional shift control mechanism. This results in a more complicated structure, which is difficult to realize from a manufacturing standpoint, and rather a method of improving the conventional shift valve has been desired. The purpose of the present invention is to focus on the above-mentioned problems, and to improve the conventional shift valve in order to add a hysteresis effect to the shift characteristics in order to stabilize the operation of the automatic transmission near the shift point. be. The automatic transmission control device of the present invention comprises an input shaft, an output shaft, a transmission gear mechanism provided between the two shafts, and a plurality of friction elements including a friction clutch or a friction brake. In a control device for an automatic transmission, the gear ratio of multiple forward gears and the gear ratio of reverse gear can be obtained by appropriately engaging or disengaging the gear ratio.
A hydraulic pressure source, a pressure regulating valve that controls the hydraulic pressure generated by the hydraulic source, an oil chamber that introduces line pressure controlled by the operation of the pressure regulating valve to operate the friction element, and a pressure regulating valve that is expressed as a function of vehicle speed. A governor valve that generates a governor pressure that is expressed as a function of a drive engine load, a throttle valve that generates a throttle pressure that is expressed as a function of a drive engine load, and a shift valve that inputs the throttle pressure and governor pressure and switches between low speed and high speed. , the shift valve includes an oil chamber for inputting the throttle pressure, a sleeve for switching the supply of the governor pressure or line pressure, a spring provided to resist the throttle pressure received by the sleeve, and a spring for resisting the throttle pressure received by the sleeve. an oil chamber to enter the
The spool has a spool that opens (closes) an oil passage connected to the friction element when the oil pressure is above a predetermined value and closes (open) when the oil pressure is below a predetermined value. An oil chamber is formed to input the line pressure or governor pressure which is switched and supplied from the sleeve when the pressure exceeds a certain value. An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows an automatic transmission to which the present invention is applied, including an overdrive ratio of a main transmission 40 with three forward speeds and one reverse speed, and an auxiliary transmission (overdrive device) 50. A one-speed automatic transmission is shown. The automatic transmission of the present invention includes an output shaft 1 of a prime mover, a torque converter 2, an input shaft 3, intermediate shafts 4, 5, 6,
Output shaft 7 and three sets of planetary gear mechanisms 8, 9, 1
0, are arranged concentrically, and three more clutches 1
1, 12, 13, 3 brakes 14, 15, 1
6 and two one-way clutches 17 and 18. The main transmission 40 includes an intermediate shaft 4 (output shaft of the sub-transmission 50), 5, 6, an output shaft 7, two sets of planetary gear mechanisms 9, 10, two clutches 12, 13, two brakes 15, 16, one one-way clutch 18, and the intermediate shaft 4 is composed of two clutches 12, 1
3 to intermediate shafts 5 and 6, respectively. The two sets of planetary gear mechanisms 9 and 10 have sun gears 21 and 2, respectively.
5. Consists of planetary pinions 22, 26, ring gears 23, 27, and carriers 24, 28. The intermediate shaft 5 is the ring gear 2 of the planetary gear mechanism 10
7, and the intermediate shaft 6 is connected to sun gears 21 and 25 of planetary gear mechanisms 9 and 10, and is provided with a brake 15. The output shaft 7 is the ring gear 2 of the planetary gear mechanism 9
3 and to the carrier 28 of the planetary gear mechanism 10. The carrier 24 of the planetary gear mechanism 9 is equipped with a one-way clutch 18 and a brake 16. Sub-transmission 50 disposed at the front of main transmission 40
is composed of an input shaft 3, an intermediate shaft 4 (output shaft of the auxiliary transmission 50), a planetary gear mechanism 8, a clutch 11, a brake 14, and a one-way clutch 17. The planetary gear mechanism 8 includes a sun gear 29, a planetary pinion 30, a ring gear 31, and a carrier 32. The carrier 32 is connected to the input shaft 3, and the ring gear 31 is connected to the intermediate shaft 4. A clutch 11 and a one-way clutch 17 are provided between the carrier 32 and the sun gear 29. Also sun gear 29
is equipped with a brake 14. Clutches 11, 12, 13, brakes 14, 15, 16, one-way clutch 17,
The 18 operations are summarized in Table 1.

[Table] In Table 1, the ○ mark indicates that the hydraulic oil operating mechanism is operating. The symbol △ indicates that the engine brake is being operated by the pressurized oil operating mechanism when necessary. The * mark indicates that the one-way clutch is locked only when the engine is driving. Note that the explanation of the operation for each gear stage is well known and therefore does not need to be explained. FIG. 2 is a hydraulic circuit showing an embodiment of the hydraulic control device of the present invention. This hydraulic control device is oil retainer 1
00, oil pump 101, pressure adjustment valve 200, speed selection valve 210, 1-2 shift valve 220, 2-3 shift valve 230, throttle valve 240, cutback valve 250, governor valve 260, overdrive shift valve 270, solenoid valve 280, relief valve 29
0, check valve 300, 310, 320, 33
0,340,350,360,370, various valves of accumulators 380,390,400 and other clutches 11,12,13 and brakes 14,
Hydraulic cylinders 410, 420, 430, 44 which are the hydraulic chambers of the hydraulic pistons that actuate the hydraulic pistons 15, 16.
0,450,460, and other various valves and various hydraulic circuits arranged between the hydraulic cylinders. The operation of this hydraulic control device will be explained below. The oil pump 101 is the supply source for the working oil pressure of the hydraulic control device, the working oil of the torque converter 2, and lubricating oil for each part.
01 is driven, oil is sucked in from the oil retainer 100 and discharged into the oil passage 102. Oil road 10
Oil pressure 2 is the source of all working oil pressure and is called line pressure. The line pressure is adjusted to a predetermined pressure by a pressure regulating valve 200 as described later. Relief valve 2
90 is a relief valve used when line pressure becomes abnormally high. Oil passage 103 passes through pressure regulating valve 200
Oil is supplied to the torque converter 2 and each lubricating point. The speed selection valve 210 consists of a spool 211 that is moved by operating the driver's seat lever, and depending on the lever selection position, the line pressure of the oil passage 102 is changed to the oil passages 104, 105, 106, etc. as shown in Table 2.
It serves as a guide to 107.

[Table] The ○ mark in Table 2 indicates that the line pressure is guided to the oil passage marked with ○ at each selected position, and the - mark indicates that the line pressure is guided to the oil passage marked in that column at the selected position. It means that there is no. The operation of the transmission at each position is: R position is reverse, N position is neutral, D
Position is forward 4 speed automatic transmission, 2 position is forward 1st speed,
Automatic shifting between the second speed and the L position is the fixed position for the first forward speed. In the D position, line pressure is sent from the oil passage 104 to the hydraulic cylinder 420 via the check valve 310 and the accumulator 380, so that the clutch 12 is always engaged. Further, in the first, second, and third forward speed states, the clutch 11 is engaged as will be described later. The oil passage 104 changes the line pressure to the 1-2 shift valve 22.
0 and governor valve 260. The 1-2 shift valve 220 is composed of spools 221, 222 and a spring 223. In the first speed, the spool 221 is located at the lower side in the figure and does not guide the pressure oil in the oil passage 104 to either direction. Oil passage 11 in 2nd, 3rd and 4th speeds
The spool 221 moves upward in the drawing due to the action of the governor pressure from the governor pressure 1, and guides the pressure oil in the oil passage 104 to the oil passage 112. The oil passage 112 communicates with the 2-3 shift valve 230, and when the spool 231 is located at the lower position in the figure, the oil passage 114 and the check valve 34 are connected.
0, brake 15 via the accumulator 400
Send pressure oil to the hydraulic cylinder 450 of the brake 15
Activate. When the brake 15 is engaged, the first
As shown in the table, the power transmission mechanism is in the second speed state. The 2-3 shift valve 230 has a spool 231,
232 and a spring 233, the first
In the third and fourth speeds, the spool 231 is moved upward in the figure due to the action of the governor pressure from the oil passage 111, and the pressure oil in the oil passage 112 is lowered. is introduced into the oil path 113, check valve 320, and accumulator 390.
Pressure oil is sent to the hydraulic cylinder 430 of the clutch 13 via the clutch 13 to operate the clutch 13. Also oil road 1
14 is connected to the oil drain port 235, and the hydraulic cylinder 4
The pressure oil in 50 flows through the oil passage 114 to the oil drain port 235.
The brake 15 is released. When the brake 15 is released and the clutch 13 is engaged, the power transmission mechanism enters the third speed state as shown in Table 1. Overdrive shift valve 270 is spool 27
1, sleeve 272, spring 273, oil chamber 2
62, 274, 275, 276, 277, oil chamber 262, 274, 275, 276, 27
Oil passage 102 and oil passage 11 depending on the pressure oil acting on 7.
7 or oil passage 118. Solenoid valve 280 is controlled by an overdrive selector switch 500 provided at the driver's seat. When overdrive selector switch 500 is OFF, opening 284 is closed. The pressure oil supplied through the oil passage 102 is supplied to the oil passage 119 and the check valve 3.
50, oil path 120, check valve 370, oil path 12
2 to the oil chamber 275 of the overdrive shift valve 270, and holds the spools 271, 279 and the sleeve 272 at the lower position in the figure. When overdrive selector switch 500 is ON, opening 284 is opened. Pressure oil in the oil chamber 275 is discharged from the oil drain port 285 via the oil passage 122, the check valve 370, the oil passage 120, the check valve 350, the oil passage 119, and the opening 284. Throttle pressure is supplied to the oil chamber 262 from the oil passage 108, and the oil chamber 262
Governor pressure is supplied to 74 from oil passage 111, and spool 271 is controlled in relation to the sizes of both. When the overdrive selector switch 500 is OFF, the line pressure of the oil passage 102 is acting on the oil chamber 275 of the overdrive shift valve 270, so the spools 279, 271 and the sleeve 27
2 is held at the lower side in the figure, and the pressure oil in the oil passage 102 is supplied to the clutch 11 via the oil passage 117 and the check valve 300.
The clutch 11 is actuated by the hydraulic cylinder 410. When the overdrive selector switch 500 is ON, the oil chamber 2 of the overdrive shift valve 270
Throttle pressure is applied to the oil passage 75 from the oil passage 108. The spool 271 of the overdrive shift valve 270 is controlled by the pressure oil acting on the oil chamber 274, the oil chamber 275, and the oil chamber 262, and is located at the lower position in the figure in the first, second, and third speed states where the governor pressure is low. The pressure oil in the oil passage 102 is removed from the oil passage 117 and the check valve 30.
0 to hydraulic cylinder 410 through clutch 1
Activate 1. When the governor pressure increases and the spool 271 moves upward in the figure, the oil passage 117 is connected to the oil drain port 278, the clutch 11 is released, and the oil passage 1
02 pressure oil is sent to the hydraulic cylinder 440 of the brake 14 via the oil passage 118 and the check valve 330, and the brake 14 is operated to enter the fourth speed (overdrive) state. In the second position, line pressure is supplied to oil passage 104 and oil passage 105. The pressure oil led to the oil passage 105 is led to the oil chamber 234 of the 2-3 shift valve 230, and holds the spools 231 and 232 in the downward direction in the figure.
In addition, check valve 350, oil passage 120, check valve 3
70, a spool 271 guided to the oil chamber 275 of the overdrive shift valve 270 via the oil passage 122;
279, hold the sleeve 272 in the downward direction shown in the figure.
The pressure oil in the oil passage 104 is guided to the hydraulic cylinder 420 of the clutch 12 and also to the 1-2 shift valve 220.
guided by. When the 1-2 shift valve 220 is not in the first speed state, the pressure oil in the oil passage 104 is transferred to the oil passage 11.
2, 114 to the hydraulic cylinder 450, and the brake 15 is actuated. clutch 11,1
2. When the brake 15 is engaged, the power transmission mechanism enters the second speed state as shown in Table 1. 1-
When the 2-shift valve 220 is in the first speed state, the spool 221 moves downward in the drawing, the oil passage 112 is connected to the oil drain port 225, and the pressure oil in the hydraulic cylinder 450 is drained via the oil passages 114 and 112. It is discharged from the port 225, the brake 15 is released, and the power transmission mechanism is placed in the first speed state. In the L position, oil passages 104, 105, 10
Line pressure is introduced to 6. The pressure oil led to the oil passage 104 operates the clutch 12 in the same manner as in each gear position in the D position. The pressure oil guided to the oil passage 105 passes through the oil chamber 234 and holds the spools 231 and 232 of the 2-3 shift valve 230 in the downward direction in the figure, and also holds the spool 2 of the overdrive shift valve 270.
71, 279, and hold the sleeve 272 in the lower position shown in the figure. The pressure oil guided to the oil passage 106 acts on the oil chamber 224 of the 1-2 shift valve 220, and the spool 221,
222 in the lower part of the figure, and the oil passage 11
6 to the hydraulic cylinder 460 of the brake 16 to operate the brake 16. When the clutches 11, 12 and brake 16 are engaged in this way, the power transmission mechanism is transferred to the first
Be in a state of speed. At the R position, line pressure is introduced into the oil passages 106 and 107. The pressure oil led to the oil passage 107 is led to the oil chamber 206 of the pressure regulating valve 200 and acts to increase the line pressure, and is also led to the oil passage 113 via the 2-3 shift valve 230 and operates the clutch 13. Activate. Moreover, the pressure oil in the oil passage 107 is 1-
The oil is guided to the oil passage 116 via the second shift valve 220 and operates the brake 16. Clutch 11 is also actuated. In this way, clutches 11, 13,
When the brake 16 is engaged, the power transmission mechanism enters the reverse state as shown in Table 1. Governor valve 260 is attached to output shaft 7 in FIG. The governor valve 260 has a hydraulic pressure (governor pressure) that is a function of the output shaft rotational speed due to a balance between centrifugal force, spring force, and hydraulic pressure, that is, a hydraulic pressure that increases as the output shaft rotational speed increases. is occurring in the oil passage 111. The throttle valve 240 includes a spool 241, a downshift plug 242, and springs 243, 24.
4. Consisting of oil chambers 245 and 246, the force of the spring 244 due to the movement of the downshift plug 242 in conjunction with the movement of the accelerator pedal and the oil chamber 245,
246, a throttle pressure proportional to the throttle opening is generated in the oil passage 108. The throttle pressure of the oil passage 108 is 1
- communicated with the overdrive shift valve 270 via the 2-2 shift valve 220 and the 2-3 shift valve 230;
The timing of gear changes is controlled according to the engine load condition. Also, when you need to downshift, press the accelerator pedal hard and the downshift plug 242
moves upward, the oil passage 102 communicates with the oil passage 109, and the line pressure of the oil passage 102 passes through the oil passage 109 to overdrive via the 1-2 shift valve 220, the 2-3 shift valve 230, and the check valve 370. Guided to the shift valve 270, the spools 221, 23
A downshift is performed from 4th speed to 3rd speed, from 3rd speed to 2nd speed, or from 2nd speed to 1st speed in balance with the governor pressure acting on the lower end of the gear. The cutback valve 250 generates cutback pressure in the oil passage 110 by balancing pressure oil.
The cutback pressure in the oil passage 110 is controlled by the throttle valve 24.
0 to lower the throttle pressure and prevent unnecessary power loss due to the oil pump. The pressure regulating valve 200 generates line pressure in the oil passage 102 by the balance between the pressure oil and the force of the spring 203. Check valve 300, 310, 320, 330,
340 is composed of a check ball, an orifice, and a hole, respectively. Accumulators 380, 390 and 400 control the supply of pressure oil to hydraulic cylinders 420, 430 and 450 of clutches 12 and 13 and brake 15, respectively, to relieve shock when the clutches and brakes are engaged. Next, regarding the shift control during 3-4 upshift and 4-3 downshift, which is the gist of the present invention, based on the first, second, and third embodiments, FIG.
This will be explained with reference to FIGS. 4, 5, and 6. First embodiment...When the governor pressure acting on the oil chamber 274 is below a predetermined value and the throttle pressure acting on the oil chamber 262 is below a certain value (force of the spring 273), the sleeve 272 Oil road 1
11 and the oil passage 121 are closed, and the pressure oil in the oil passage 121 is discharged from the discharge port 268. If the pressure oil is above a certain value, the oil passage 111 and the oil passage 1
21 is opened, governor pressure acts on the oil chamber 277 formed by the area difference between lands 271a and 271b, and a first hysteresis pressure is generated, which is formed by the area difference between lands 271b and 271c. The line pressure acts on the oil chamber 276, and together with the second hysteresis pressure generated, a force is applied to push the spool 271 downward in the drawing. In the case of a 3-4 upshift, when the throttle pressure acting on the oil chamber 262 is below a certain value, the governor pressure acting on the oil chamber 274 increases as the vehicle speed increases, and the spool 271 due to the governor pressure increases. The vehicle speed becomes a shift point at which the upward force is greater than the force of the first hysteresis pressure and the spring 273 that pushes the spool 271 downward in the figure, pushing the spool 271 upward in the figure, and finally the oil chambers 276, 277 Pressure oil is discharged from the discharge ports 278 and 265 respectively, and the oil passage 1
18 and 102 are connected, and the pressure oil in the oil passage 102 is guided to the oil passage 118 and the brake 14 is engaged, and at the same time, the pressure oil in the oil passage 117 is discharged from the discharge port 278.
Clutch 11 is released and the 3-4 upshift is completed. When the throttle pressure is above a certain value, the governor pressure acting on the oil chamber 274 increases as the vehicle speed increases, and the force of pushing the spool 271 upward in the figure due to the governor pressure increases to the first and second
The shift point is the vehicle speed that is greater than the force that pushes the spool 271 downward in the drawing due to the hysteresis pressure and the throttle pressure acting on the oil chamber 262. Therefore, as shown in FIG. 6, when the throttle opening is equal to or greater than a certain value p, a hysteresis width a corresponding to the hysteresis pressure acting on the oil chamber 277 is imparted to the speed change characteristics. In the case of 4-3 downshift, when the throttle pressure acting on the oil chamber 262 is below a certain value, the governor pressure acting on the oil chamber 274 decreases as the vehicle speed decreases, and the spool 271 due to the governor pressure decreases. The vehicle speed at which the upward force pushing the spool 271 is smaller than the force pushing the spool 271 downward as shown in the figure by the spring 273 is the shift point.
71 downward in the figure, the pressure oil in the oil chamber 266 is discharged from the discharge port 267, and the oil passages 117 and 102 are
When the pressure oil in the oil passage 102 is guided to the oil passage 117 and the clutch 11 is engaged, the oil passage 118 is simultaneously connected.
Pressure oil is discharged from the discharge port 267 and the brake 14
is released and the 4-3 downshift is completed. When the throttle pressure is above a certain value, the governor pressure acting on the oil passage 274 decreases as the vehicle speed decreases, and the force of the governor pressure pushing up the spool 271 upward in the figure increases the throttle pressure acting on the oil chamber 262. The speed change point is the vehicle speed that is smaller than the force that pushes the spool 271 downward in the figure. Therefore, as shown in FIG. 6, when the throttle opening is below a certain value p, a hysteresis width corresponding to the second hysteresis pressure acting on the oil chamber 276 is applied to the speed change characteristics, and when the throttle opening is above P, Sometimes, a hysteresis width a+b corresponding to the first and second hysteresis pressures is added to the speed change characteristic. (3rd
(See Fig. 6) Second embodiment...Overdrive shift valve 27
0 is the spool 271, 612, the sleeve 601,
Spring 606, oil chamber 274, 275, 27
6,277, the spool 271 has lands 271a, 271b, 271c with different areas, and each pressure oil has a discharge port 261, 265, 267, 2
78,605. In this embodiment, the line pressure supplied to the oil passage 117 acts on the oil chamber 277. Below, 3-4 upshift, 4-3
The downshift operation is the same as in the first embodiment. (See Figures 4 and 6) Third embodiment... Overdrive shift valve 27
0 is the spool 271, 611, the sleeve 603,
Spring 606, oil chamber 274, 275, 27
6,277, the spool 271 has lands 271a, 271b, and 271c with different areas, and the sleeve 613 has an outlet 609 and an inlet 71.
1, each pressure oil has a discharge port 265, 267, 27
8,605. In this embodiment, the line pressure supplied to the oil passage 117 acts on the oil chamber 277. Hereinafter, the operations of 3-4 upshift and 4-3 downshift are the same as in the first embodiment. (See Figures 5 and 6) As explained above, the overdrive shift valve has been improved to reduce the hysteresis effect during 3-4 upshifts and 4-3 downshifts when the throttle opening is above a certain value. This is applied regardless of the throttle opening, allowing smooth gear shifting, especially when climbing hills or driving on roads with steep ups and downs. Furthermore, it is easy to understand that the present invention is not limited to overdrive shift valves as in the embodiments, but can be applied to other shift valves in the same manner.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the power transmission mechanism of an automatic transmission to which the present invention is applied, FIG. 2 is a hydraulic circuit diagram of a first embodiment of the hydraulic control device of the present invention, and FIG. FIG. 4 is a vertical cross-sectional view showing the main parts of the second embodiment of the present invention, and FIG. 5 shows the main parts of the third embodiment of the present invention. The vertical cross-sectional view and FIG. 6 are transmission diagrams obtained by the apparatus according to the embodiment of the present invention. Explanation of the numbers, 40...Main transmission, 50...Sub-transmission, 100...Oil retainer, 101...Oil pump,
200...Pressure regulating valve, 210...Speed selection valve, 22
0... 1-2 shift valve, 230... 2-3 shift valve, 240... Throttle valve, 250... Cutback valve, 260... Governor valve, 270... Overdrive shift valve, 280... Solenoid valve,
290...Relief valve, 300, 310, 32
0,330,340...Check valve, 380,3
90,400...Accumulator, 410,42
0,430,440,450,460...Hydraulic cylinder.

Claims (1)

[Claims] 1 Consists of an input shaft, an output shaft, a transmission gear mechanism provided between the two shafts, and a plurality of friction elements including a friction clutch or a friction brake, and the friction elements are engaged or released as appropriate by hydraulic pressure. A control device for an automatic transmission that can obtain multiple forward gear ratios and reverse gear ratios includes a hydraulic pressure source, a pressure regulating valve that controls the hydraulic pressure generated by the hydraulic source, and an oil chamber that introduces line pressure controlled by the operation of a pressure regulating valve to operate the friction element; a governor valve that generates a governor pressure expressed as a function of vehicle speed; and a governor pressure expressed as a function of drive engine load. A throttle valve that generates a throttle pressure such as the above, and a shift valve that inputs the throttle pressure and governor pressure to switch between low speed and high speed, and the shift valve has an oil chamber that inputs the throttle pressure, and an oil chamber that inputs the throttle pressure, and a shift valve that inputs the throttle pressure and the governor pressure. A sleeve that switches the pressure supply,
A spring provided to resist the throttle pressure received by the sleeve, an oil chamber that inputs the governor pressure, and an oil passage that opens (closes) communicating with the friction element when this oil pressure exceeds a predetermined value. ) and a spool that closes (opens) when the value is below a predetermined value,
A control device for an automatic transmission, wherein the spool forms an oil chamber into which the line pressure or governor pressure that is switched and supplied from the sleeve is input when the throttle pressure is above a certain value.