JPH06207667A - Belt type continuously variable transmission controller - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To ensure startability when the control device of the belt type continuously variable transmission is abnormal, and to regulate the line pressure to an appropriate hydraulic pressure. [Structure] Interposed between a gear ratio control hull 16 and a regulator valve 15 and opened when the control oil pressure is low, and when the manual valve 9 is at a low speed stage or a retreat position, a predetermined oil pressure is applied to the gear ratio control valve 16 and While supplying to the regulator valve 15 to shift to the low speed side,
Adjust the line pressure to a level sufficient for traveling, supply a predetermined hydraulic pressure only to the regulator valve when the vehicle is in the position of the high speed stage, and regulate the line pressure to a level sufficient for traveling. When the supply of hydraulic pressure to the regulator valve is stopped to adjust the line pressure to a low level and the control hydraulic pressure is high, the gear shift limiting valve 18, the gear ratio control valve 16, the gear ratio limiting valve, and the regulator valve of the vehicle are provided. Control valves 8 and 19 for supplying control hydraulic pressures according to operating conditions are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt type continuously variable transmission control device.

[0002]

2. Description of the Related Art A belt type continuously variable transmission is a transmission that uses a belt and a pulley to continuously change a gear ratio, and as shown in FIG. 1, an engine, an electromagnetic clutch, a fluid coupling, etc. A primary pulley (input shaft) 1 driven via a not shown), a secondary pulley (output shaft) 2 connected to a front axle, and a primary pulley 1 and a secondary pulley 2 that are wound around the primary pulley 1 and the secondary pulley 2. The belt 3 and the hydraulic control device 4 that controls the groove widths Wp and Ws of the primary pulley 1 and the secondary pulley 2 are configured.

Primary pulley 1, secondary pulley 2
Is provided with shafts 1a and 2a having predetermined inclined surfaces, movable sheaves 1b and 2b, and primary cylinders 1c and secondary cylinders 2c provided on the back surfaces of the movable sheaves 1b and 2b, respectively. , Ball splines are slidable on the shafts 1a, 2a, and a primary hydraulic pressure P supplied from the hydraulic control device 4 is supplied.
p, groove width Wp, Ws of the pulley by the secondary hydraulic pressure Ps
Can be changed. The hydraulic control device 4 includes an electronic control device (not shown),
Groove width W of the primary pulley 1 and secondary pulley 2 is controlled by inputting respective signals such as engine speed and vehicle speed and controlling the hydraulic pressure supplied from the hydraulic pump 5 based on these signals.
Control p, Ws.

That is, in the low state, as shown in FIG. 2, the groove width Wp of the primary pulley 1 is wide, the groove width Ws of the secondary pulley 2 is narrow, and the gear ratio is large. On the contrary, in the overdrive state, as shown in FIG. 3, the groove width Wp of the primary pulley 1 is narrow, the groove width Ws of the secondary pulley 2 is wide, and the gear ratio is small. The hydraulic device 4
As shown in FIG. 4, the gear ratio control valve 6, the gear shift limiting valve 7,
The solenoid valve 8 and the manual valve 9 are included. The solenoid valve 8 is a normally closed type valve, and is duty-controlled by the electronic control unit in accordance with a vehicle operating state such as an accelerator opening degree, an engine speed, a vehicle speed. The solenoid valve 8 is supplied with a predetermined solenoid supply pressure Pv at a port 8a and outputs a control oil pressure (hereinafter simply referred to as "control pressure") Pva (≤Pv) from the port 8b to control a gear ratio. Supply to the valve 6 and the shift limiting valve 7. The duty ratio of the solenoid valve 8 is large when the gear ratio is on the low speed side, and is small when the speed ratio is on the high speed side.
Becomes lower as the speed shifts from the low speed side to the high speed side.

The high-pressure oil pressure discharged from the hydraulic pump 5 is adjusted to a predetermined line pressure PL by a regulator valve (not shown) and supplied to the secondary cylinder 2c to narrow the groove width Ws of the secondary pulley 2. Act as you do. When the control pressure Pva of the solenoid valve 8 is high, the control pressure Pva supplied to the port 6c of the gear ratio control valve 6 pushes the spool 6p to the left in the figure against the spring pressure of the spring 6s, and the port 6a. Is blocked from 6b and communicated with the port 6x, and the oil in the primary cylinder 1c is gradually discharged from the discharge port 6x.
As a result, the groove width Wp of the primary pulley 1 as shown in FIG.
Is the maximum, the groove width Ws of the secondary pulley 2 is the minimum,
The gear ratio becomes a low speed stage.

When the control pressure Pva of the solenoid valve 8 becomes low, the spring 6s pushes the spool 6p to the right in the figure accordingly, the ports 6a and 6b are gradually communicated, and the line pressure PL becomes the primary cylinder 1c. Is supplied to. The primary cylinder 1c is the secondary cylinder 2
The pressure receiving area is larger than c (FIG. 1). Therefore, as the line pressure PL is supplied to the primary cylinder 1c, the pressing force of the primary cylinder 1c is increased by the secondary cylinder 2c.
And the groove width Wp of the primary pulley 1 is gradually narrowed, and accordingly, the groove width Ws of the secondary pulley 2 is widened, and the gear ratio is gradually changed to the higher gear side.

When the control pressure Pva of the solenoid valve 8 is further lowered, the spring 6s pushes the spool 6p further to the right in the figure, and the ports 6a and 6b are completely connected. As a result, as shown in FIG. 3, the groove width Wp of the primary pulley 1 is minimum, the groove width Ws of the secondary pulley 2 is maximum, and the gear ratio is in the overdrive state. The solenoid valve 8 uses a part of the control pressure Pva as the shift limiting valve 7
To the spool 7 against the spring force of the spring 7s.
By pushing p to the left in the figure, the ports 7a and 7b are cut off, and the oil passage connecting the ports 9b and 9c of the manual valve 9 and the port 6d of the gear ratio control valve 6 is cut off. When the solenoid valve 8 fails for some reason and the control pressure Pva becomes equal to or lower than a predetermined pressure, the spool 7p of the shift limiting valve 7 is pushed to the right by the spring 7s as shown in the figure, and the ports 7a and 7b are communicated with each other. , The ports 9b and 9c of the manual valve 9 and the ports 6d of the gear ratio control valve 6 are communicated with each other via the one-way valves 13 and 14. At this time, in the gear ratio control valve 6, the spool 6p is pushed to the right in the drawing, the port 6a is communicated with the port 6b, and the high speed stage side (overdrive state) is switched.

The clutch supply pressure Pc for driving the forward clutch 11 or the reverse brake 12 only when the shift position of the maneuver valve 9 is L (low speed range) or R (reverse), for example, as shown in FIG. When in the L position, the clutch supply pressure Pc passes through the one-way valve 13 and the ports 7a and 7b of the shift limiting valve 7 and the gear ratio control valve 6
Is supplied to the port 6d of the
It is pushed to the left against s and switched to the low speed stage side (low state). Therefore, when the solenoid valve 8 breaks down and the control pressure Pva falls below the predetermined pressure when the vehicle normally travels in the D range, the transmission shifts to the high speed side immediately after the breakdown, so that the speed changes rapidly. There is no risk of over-rotation of the engine due to such a downshift, and by changing the shift position of the manual valve 9 as necessary, it becomes possible to travel even on the low speed stage side, and sufficient climbing performance can be obtained.

[0009]

However, since the line pressure PL is not regulated when the electronic control unit is out of order in the above configuration, when the line pressure PL is set to the maximum pressure, the high pressure side An excessive load is applied to the belt 3 during traveling, impairing the durability of the belt. In addition, the startability may be deteriorated, and the engine may not be able to start at low temperatures. On the other hand, when the line pressure PL is set to the minimum pressure, the belt slips when running on the low speed stage side, so that not only sufficient climbing performance cannot be obtained but also the durability of the belt may be impaired. I have a problem.

The present invention has been made in view of the above points, and adjusts the line pressure to an appropriate hydraulic pressure without impairing the startability when an abnormality occurs in the electronic control unit for controlling the transmission, An object of the present invention is to provide a control device for a belt type continuously variable transmission that ensures sufficient running performance and improves the durability of the belt.

[0011]

To achieve the above object, according to the present invention, a belt is wound between a primary pulley and a secondary pulley provided on an input shaft and an output shaft, and hydraulic pressure is applied to each pulley. The hydraulic pressure of each pulley of the belt type continuously variable transmission that changes the groove width relatively is controlled, and when the supplied control hydraulic pressure is high, the transmission is set to the low speed side, and when it is low, the high speed side is set. A gear ratio control valve for shifting, a regulator valve for setting a line pressure to be supplied to the transmission, a manual valve, and the gear ratio control valve and the regulator valve are interposed and are opened when the control oil pressure supplied is low. When the manual valve is in the low speed stage or in the reverse position, a predetermined hydraulic pressure is applied from the manual valve to the transmission ratio control valve and the regulator. Supply to the valve to shift the speed ratio control valve to the low speed stage side, adjust the regulator valve to a line pressure sufficient for traveling, and set the predetermined hydraulic pressure when the manual valve is at the high speed stage position. Is supplied only to the regulator valve to adjust the line pressure, and when the manual valve is in the parking position or the neutral position, the supply of the predetermined hydraulic pressure to the regulator valve is stopped to adjust the line pressure to a low line pressure. A shift control valve that is closed when the control oil pressure is high; a first control valve that supplies the control oil pressure to the gear ratio control valve and the shift control valve according to the operating state of the vehicle; And a second control valve for supplying a control oil pressure according to the operating state of.

[0012]

In the normal operation, the first control valve closes the gear shift limiting valve and shuts off the manual valve from the gear ratio control valve and the regulator valve. As a result, the gear ratio control valve controls the gear ratio by the control oil pressure of the first control valve. Further, the line pressure of the regulator valve is adjusted by the control oil pressure of the second control valve. While running on the high speed stage side, the first and second
When the control oil pressure of each control valve becomes low, the gear shift limiting valve opens, the gear ratio control valve is controlled to the high speed side, and the regulator valve is controlled to regulate the line pressure to a level high enough for traveling. To be done. Then, when the manual valve is operated to the low speed stage or the retracted position, hydraulic pressure of a predetermined pressure is supplied from the manual valve to the gear ratio control valve and the regulator valve. The gear ratio control valve shifts the transmission to a low speed stage when the hydraulic pressure of the predetermined pressure is supplied. This ensures startability and climbability. Further, the regulator valve regulates the line pressure so as to increase when the hydraulic pressure of the predetermined pressure is supplied, and stops the supply of the predetermined hydraulic pressure to the regulator valve when the manual valve is in the parking position or the neutral position. Keep line pressure low. This prevents the belt from slipping even when the input torque on the low speed stage side is large, and keeps the line pressure low at the time of starting to improve the startability.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. The same members as those in FIG. 4 are designated by the same reference numerals. In FIG. 5, the regulator valve 15 has spools 15p and 15p ', and the spool 15p' is integrally formed with a land 15m having the same diameter as the spool 15p and a land 15n slightly larger than the land 15m. The land 15m is a spring seat. Spool 1
A spring 15s is provided between one end of 5p and the spring seat 15g.
A springs 15sb are respectively compressed between the other end of the spool 15p and the land 15m of the spool 15p '. The gear ratio control valve 16 has spools 16p and 16p 'similarly to the regulator valve 15,
The spool 16p 'is a land 1 having the same diameter as the spool 16p.
6m and land 16n are integrally formed, and land 16m
Is a spring seat. A spring 16sa is provided between one end of the spool 16p and the end surface of the housing, and the other end of the spool 16p and the land 16m of the spool 16p ′ are provided.
The springs 16sb are respectively compressed between and.

Port 15b of regulator valve 15
Is connected to the discharge port of the hydraulic pump 5 and is also connected to the port 16b of the gear ratio control valve 16, and the port 15xp is connected to the suction port side of the hydraulic pump 5 at the port 15c.
Is connected to port 19b of solenoid valve 19 and port 1
5d is connected to the port 18d of the shift limiting valve 18. The port 16a of the gear ratio control valve 16 is connected to the primary cylinder 1c, the port 16b is connected to the secondary cylinder 2c, the port 16c is connected to the port 8b of the solenoid valve 8, and the port 16d is connected to the port 18a of the speed limit valve 18. Has been done. The discharge port 16x is connected to the primary pressure discharge valve 17.

The port 9b of the manual valve 9 is connected to the port 18b of the shift limiting valve 18 via the one-way valve 13, and the port 9c is connected to the reverse brake 12 and the shift limiting via the one-way valve 14. The port 18 b of the valve 18 is connected, and the port 9 f is connected to the port 18 c of the shift limiting valve 18 via the one-way valve 21. Furthermore, upstream of the one-way valve 14 and the reverse brake 1
The oil passage between the downstream side of 2 and the downstream side of 2 is connected to the port 18c via the one-way valve 22. The ports 9d and 9e are connected to the forward clutch 11.

The one-way valves 13 and 14 are connected so as to allow the flow of oil only from the ports 9b and 9c of the manual valve 9 toward the port 18b of the speed change limiting valve 18,
The one-way valves 21 and 22 are the ports 9 of the manual valve 9.
It is connected so as to allow the flow of oil only from f and 9c toward the port 18c of the shift limiting valve 18. The port 18e of the shift limiting valve 18 is connected to the port 8b of the solenoid valve 8. Then, the port 18a of the shift limiting valve 18 and the port 1 of the gear ratio control valve 16
6d and the port 18d and the port 15d of the regulator valve 15 are connected to the respective oil passages through the ports 16d and 15
Orifices 25 and 26 are provided immediately upstream of d, respectively.

The solenoid valves 8 and 19 are supplied with the solenoid supply pressure Pv to the respective ports 8a and 19a on the input side. These solenoid valves 8 and 19 are driven by the electronic control unit. The solenoid valve 19 is a normally closed type valve, like the solenoid valve 8, and is duty-controlled to output a control pressure Pvb (≦ Pv) corresponding to the duty ratio from the port 19b and supply it to the port 15c of the regulator valve 15. .

The regulator valve 15 is a hydraulic pump 5.
The high pressure oil pressure discharged from the secondary cylinder 2c and the gear ratio control valve 16 is adjusted to a predetermined line pressure PL.
Supply to the port 16b. Also, this line pressure PL
Is also supplied to the port 15a of the regulator valve 15. The manual valve 9 communicates with the ports 9a, 9d, and 9e when the shift position is the illustrated L position and the second position, and communicates with the ports 9a and 9d when the shift position is the D position, so that the clutch supply pressure Pc is applied to the forward clutch 11. Supplied,
At the N position, the port 9a is cut off from the other ports 9b to 9f, at the R position, the ports 9a and 9c are communicated with each other, the clutch supply pressure Pc is supplied to the reverse brake 12, and at the P position, the port 9a is closed. To be done.

When the manual valve 9 is in the L position, the ports 9a, 9b and 9f are communicated with each other, the clutch supply pressure Pc is supplied to the port 18b of the shift limiting valve 18 through the one-way valve 13 and the one-way valve. 21 is supplied to the port 18c, and when in the R position, the port 9 is supplied.
The clutch supply pressure Pc is supplied from c to the port 18b of the shift limiting valve 18 through the one-way valve 14, and is also supplied to the port 18c through the one-way valve 22. That is,
When the manual valve 9 is in the L position or the R position, the clutch supply pressure Pc is supplied to the ports 18b and 18c of the shift limiting valve 18. Further, when the shift position of the manual valve 9 is other than the P position (parking) and the N position (neutral), the clutch supply pressure Pc changes from the port 9f to the shift limiting valve 1.
8 ports 18c. And one-way valve 1
3, 14, 21, and 22 are that the hydraulic pressure is simultaneously supplied to the forward clutch 11 and the reverse brake 12 when the manual valve 9 is operated to the R position and the respective forward shift positions (L, 2, D positions). Prevent.

The operation will be described below. The solenoid valves 8 and 19 are duty-controlled by the electronic control unit and output control pressures Pva and Pvb. Since the gear ratio control valve 16 does not operate unless the control pressure Pva is equal to or higher than the minimum pressure Po, the normal control pressure Pva is equal to or higher than Po (Pva ≧
The duty is controlled so that it becomes Po). on the other hand,
The gear shift limiting valve 18 controls the control pressure P of the solenoid valve 8.
When va is Po or more, the spool 18p is pushed leftward in the figure against the spring 18s, and the ports 18a and 18b and the ports 18c and 18d are closed.

Therefore, when the solenoid valve 8 is normal, the shift limiting valve 18 is closed and the regulator valve 1
5. The gear ratio control valve 16 is not cut off from the manual valve 9 and the clutch supply pressure Pc is not supplied. Therefore, even if the manual valve 9 is operated, the regulator valve 15 and the gear ratio control valve 16 are not affected at all.

The regulator valve 15 has a port 15a.
The line pressure PL is adjusted to a predetermined line pressure PL according to the pressure difference between the line pressure PL and the spring pressure of the spring 15sa and the control pressure Pvb and the spring pressure of the spring 15sb. This line pressure PL is supplied to the secondary cylinder 2c, and the groove width Ws of the secondary pulley 2 (FIG. 1) becomes narrow. In the gear ratio control valve 16, the position of the port 16p is controlled according to the differential pressure between the solenoid supply pressure Pv supplied to the port 16e, the spring pressure of the spring 16sa, and the control pressure Pva and the spring pressure of the spring 16sb. 8
When the control pressure Pva is high, the port 16a is pushed to the left as shown in the figure, and the port 16a is blocked from the port 16b and communicated with the discharge port 16x. As a result, the oil in the primary cylinder 1c is gradually discharged from the discharge port 17x of the primary pressure discharge valve 17 via the port 16x, the groove width Wp of the primary pulley 1 is widened, and the gear ratio is set to the low speed side (low side). Controlled.

When the control pressure Pva of the solenoid valve 8 becomes low, the spool 16p of the gear ratio control valve 16 is pushed to the right in the figure, the port 16a is blocked from the discharge port 16x, and is gradually communicated with the port 16b. The line pressure PL is also supplied to the primary cylinder 1c. The primary cylinder 1c has a larger pressure receiving area than the secondary cylinder 2c (FIG. 1), and therefore the pressing force of the primary cylinder 1c becomes larger than the pressing force of the secondary cylinder 2c, and as a result, the groove width Wp of the primary pulley 1 is increased.
Is narrower, the groove width Ws of the secondary pulley 2 is wider, and the gear ratio is controlled to the higher gear side.

When the control pressure Pva of the solenoid valve 8 is further lowered, the spool 16p is pushed further to the right in the figure, and the ports 16a and 16b are completely connected. As a result, as shown in FIG. 3, the groove width Wp of the primary pulley 1
Is minimum, the groove width Ws of the secondary pulley 2 is maximum, and the gear ratio is in the overdrive state. Now, it is assumed that when the manual valve 9 is running at the D position, an abnormality occurs in the electronic control unit, and the solenoid valves 8 and 19 are deenergized and closed. When the solenoid valve 8 is closed, the control pressure Pva becomes 0, and accordingly, the spool 16p of the gear ratio control valve 16 is pushed to the right in the figure, the port 16a is communicated with the port 16b, and the gear ratio is high. Side (overdrive side). As a result, engine overspeed is prevented even during high-speed running.

When the solenoid valve 8 is closed and the control pressure Pva becomes 0, the spool 18p of the shift limiting valve 18 is pushed rightward in the figure by the spring 18s.
Ports 18a and 18b, ports 18c and 18 as shown
It is communicated with d. The manual valve 9 is traveling in the D position, and therefore, the clutch supply pressure Pc passes from the port 9f of the manual valve 9 to the regulator valve 15 via the one-way valve 21, the shift limiting valve 18, and the orifice 26.
Is supplied to the port 15d.

On the other hand, when the solenoid valve 19 is closed, the control pressure Pvb becomes 0, and accordingly, the regulator valve 15 receives a pressing force that pushes the spool 15p to the right in the figure. However, the clutch supply pressure Pc is supplied to the port 15d through the orifice 26, and accordingly, the spool 15p 'is gradually pushed leftward to compress the spring 15sb. This allows the spring 15
The spring force of sb increases, and the pushing force of the line pressure PL applied to the left side of the spool 15p and the spring force of the spring 15sa is overcome to prevent the spool 15p from moving to the right. As a result, the line pressure PL of the regulator valve 15 increases. The line pressure PL at this time is adjusted to a hydraulic pressure of a sufficient height necessary for traveling.

In this state, when the manual valve 9 is operated from the D position to, for example, the L position, the clutch supply pressure Pc is supplied from the port 9b to the port 18b through the one-way valve 13, and further the port 18a and the orifice 25. Is supplied to the port 16d of the gear ratio control valve 16. When the clutch supply pressure Pc is supplied through the orifice 25, the gear ratio control valve 16 receives the spool 16p '.
Is gradually pushed to the left, and the spring 16s
b is compressed to increase the spring pressure, the spool 16p is pushed to the left, the port 16a is blocked from the port 16b, and is communicated with the discharge port 16x.

As a result, the oil in the primary cylinder 1c is gradually discharged from the discharge port 17x of the primary pressure discharge valve 17 via the discharge port 16x of the gear ratio control valve 16, and the groove width Wp of the primary pulley 1 (FIG. 1) is reduced. It will be the maximum. On the other hand, the high line pressure PL is supplied to the secondary cylinder 2c, and the groove width Ws of the secondary pulley 2 is minimized. As a result, the gear ratio is controlled to the low speed stage. The regulator valve 15 is supplied with the clutch supply pressure Pc to the port 15d via the orifice 26, and regulates the line pressure PL to a hydraulic pressure of a sufficient height as described above. The line pressure PL rises to a sufficiently high line pressure in a range excluding the vicinity of the fully opened throttle when the gear ratio is on the low speed stage side.

When the manual valve 9 is operated to the L position in this manner, the gear ratio on the low speed side is obtained. This ensures startability and climbability. Similarly, when the manual valve 9 is operated to the R position, the reverse drive is ensured. Moreover, when the manual valve 9 is operated to a position other than the P position or the N position, the line pressure PL becomes high and the belt slip is prevented.

When the manual valve 9 is in the P (parking) position, the port 9a is closed, and when the manual valve 9 is in the N (neutral) position, the port 9f is closed, and the clutch supply pressure Pc passes through the shift limiting valve 18 to the regulator valve. 15
Is not supplied to the port 15d. Therefore, the line pressure PL
Is kept low. That is, the regulator valve 15 is
When the control pressure Pva becomes equal to or lower than a certain pressure (≦ Po) and the clutch supply pressure Pv is not supplied via the shift limiting valve 18, the line pressure PL is reduced. This prevents the startability from deteriorating.

[0031]

As described above, according to the present invention, when an abnormality occurs in an electronic control device such as a solenoid valve that controls the transmission while the manual valve is traveling in the D range, the gear ratio is set to the high speed side. In addition, since the line pressure becomes a line pressure that is high enough to run on the high speed side, an excessive load is prevented from being applied to the belt, the durability of the belt is not impaired, and the input The belt will not slip when the torque is large, and the durability of the belt will not be impaired. Also, even when the input torque is large when traveling on the low speed side, the line pressure is high enough for traveling on the low speed side, so the belt does not slip and sufficient climbing performance is obtained. It is ensured and the durability of the belt is prevented from being impaired. Further, when the manual valve is operated to the P position or the N position, the line pressure is kept low, and it is possible to prevent the startability from being deteriorated.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a belt type continuously variable transmission.

FIG. 2 is a perspective view showing a state of a low speed stage side (low side) of the transmission of FIG.

FIG. 3 is a high speed stage side (overdrive side) of the transmission of FIG.
It is a perspective view showing the state.

FIG. 4 is a hydraulic circuit diagram of a conventional control device for the belt type continuously variable transmission of FIG.

FIG. 5 is a hydraulic circuit diagram showing an embodiment of a control device for a belt type continuously variable transmission according to the present invention.

[Explanation of symbols]

 1 Primary Pulley 1c Primary Cylinder 2 Secondary Pulley 2c Secondary Cylinder 3 Belt 4 Hydraulic Controller 5 Hydraulic Pump 9 Manual Valve 13, 14 One-way Valve 15 Regulator Valve 16 Gear Ratio Control Valve 8, 19 Solenoid Valve 17 Primary Pressure Discharge Valve 18 Gear Shift Restriction valve

Claims (1)

[Claims] 1. A belt-type continuously variable transmission in which a belt is wound between a primary pulley and a secondary pulley provided on an input shaft and an output shaft, and a groove width of each pulley is relatively changed by hydraulic pressure to shift gears. The hydraulic pressure of each of the pulleys is controlled so that when the supplied control hydraulic pressure is high, the transmission ratio control valve that shifts the transmission to the low speed stage side and when it is low is provided to the high speed stage side, and the line pressure supplied to the transmission. It is interposed between the regulator valve to be set and the manual valve and the gear ratio control valve and the regulator valve. When the control hydraulic pressure supplied is low, the valve is opened, and when the manual valve is in the low speed stage or the reverse position, the manual valve is opened. A predetermined hydraulic pressure is supplied from the valve to the speed ratio control valve and the regulator valve to shift the speed ratio control valve to the low speed side. The regulator valve is regulated to a line pressure sufficient for traveling, and when the manual valve is at the high speed stage side, the predetermined hydraulic pressure is supplied only to the regulator valve to regulate the line pressure. When the manual valve is in the parking position or the neutral position, the supply of the predetermined hydraulic pressure to the regulator valve is stopped to adjust the line pressure to a low line pressure, and when the control hydraulic pressure is high, the shift limiting valve is closed. A first control valve that supplies a control oil pressure to the gear ratio control valve and the gear shift limiting valve according to the operating condition of the vehicle, and a second control valve that supplies the control oil pressure to the regulator valve according to the operating condition of the vehicle. A control device for a belt-type continuously variable transmission, comprising: