JPH07117152B2 - Hydraulic control device for vehicle belt type continuously variable transmission - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an improvement of a hydraulic control device for a belt type continuously variable transmission for a vehicle.

BACKGROUND ART A pair of primary side variable pulley and secondary side variable pulley provided on a primary side rotating shaft and a secondary side rotating shaft, respectively, and a transmission belt that is wound around the pair of variable pulleys and transmits power, A belt type continuously variable transmission for a vehicle is known that includes a pair of primary side hydraulic cylinders and a pair of secondary side hydraulic cylinders that respectively change the effective diameters of a pair of variable pulleys. The speed ratio of the continuously variable transmission and the tension of the transmission belt are set so that the hydraulic oil from the hydraulic source is supplied to one of the hydraulic cylinders and simultaneously discharged from the other, as described in JP-B-58-29424. Is controlled by a hydraulic control device that includes a shift control valve (four-way valve) that changes the speed ratio by the above, and an electromagnetic relief valve that regulates the hydraulic oil that flows out from this control valve.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the speed change control valve of such a hydraulic control device, the circulation direction of the hydraulic oil is controlled by driving the spool valve element through a mechanically connected link. Therefore, it is inevitable that the neutral point of the control valve varies due to component tolerances. Therefore, it is necessary to adjust the setting of the neutral point at the time of assembling the hydraulic control device.

On the other hand, it has been considered that a pair of springs urges the spool valve elements in mutually opposite directions and positions the spool valve element at a neutral point where the urging forces are balanced. However, in such a case, there is a disadvantage that the neutral point of the spool valve element is easily displaced due to foreign matter in the hydraulic oil, changes in sliding friction, and the like.

Further, it is conceivable that the two 3-port 3-position directional control valves disclosed in JP-A-56-46152 are each constituted by two spool valve elements provided so as to be brought into contact with the stopper in the neutral state. However, in such a case, since four spool valve elements and four spool valve element driving means for independently driving the spool valve elements are required in the shift control valve device, the number of parts is large and the configuration is large. There is a drawback that the device becomes complicated and the device becomes large.

Means for Solving Problems The present invention has been made against the above circumstances.
The gist thereof is that a pair of primary side variable pulleys and secondary side variable pulleys respectively provided on the primary side rotation shaft and the secondary side rotation shaft and a pair of variable pulleys are wound around to transmit power. In a belt-type continuously variable transmission for a vehicle, which includes a transmission belt and a pair of primary-side hydraulic cylinders and secondary-side hydraulic cylinders that change the effective diameters of the pair of variable pulleys, a belt-type continuously variable transmission for a vehicle is relatively supplied from an oil pressure source. By supplying high-pressure hydraulic oil to one of the primary-side hydraulic cylinder and the secondary-side hydraulic cylinder and causing the hydraulic oil in the other to flow out, the effective diameters of the primary-side variable pulley and the secondary-side variable pulley are increased. Is a hydraulic control device including a shift control valve device for adjusting the speed ratio of the continuously variable transmission, wherein the shift control valve device is formed on a valve body. , And a pair of spool valves that are slidably fitted in the cylinder bores and are brought into contact with stoppers so that they are respectively positioned on the non-switching side and make the operation of the shift control valve device in a neutral state. A pair of a valve and a pair of valves that respectively control the supply of hydraulic oil to the one hydraulic cylinder and the outflow of hydraulic oil from the other hydraulic cylinder by driving the spool valve element from the non-switching side to the switching side. Spool valve element driving means, and one of the pair of spool valve elements supplies hydraulic oil to the primary hydraulic cylinder and discharges hydraulic oil from the secondary hydraulic cylinder on the switching side thereof. Therefore, the speed ratio is exclusively changed in the increasing direction, and the other of the pair of spool valve elements is
On the switching side, the hydraulic oil is supplied to the secondary hydraulic cylinder and the hydraulic oil in the primary hydraulic cylinder is discharged to exclusively change the speed ratio.

With this configuration, in the shift control valve device, the spool valve element driving means causes the pair of spool valve elements to come into contact with the stoppers and prevent the axial movement of the spool valve elements. The shift control valve devices are respectively positioned on the switching sides, and the operation state of the shift control valve device is set to the neutral state. Therefore, as compared with the conventional shift control valve of the type in which the circulation direction of the hydraulic oil is controlled by driving the spool valve element through a mechanically connected link, the shift due to component tolerances or the like is performed. Variations in the neutral point of the control valve are eliminated, and the work of adjusting the neutral point setting is unnecessary at the time of assembling the hydraulic control device. In addition, compared to a shift control valve in which a spool valve element is biased in opposite directions by a pair of springs, and the spool valve element is positioned at a neutral point where the biasing forces are balanced, foreign matter and sliding The deviation of the neutral point of the spool valve due to the change of dynamic friction is almost eliminated.

Further, in the shift control valve device, since it is configured by providing a pair of spool valve elements, the spool valve element and the cylinder bore can be processed more easily than in the conventional case using a single spool valve element. At the same time, there are advantages that the number of parts is small and the configuration is simple, and the device is small.

Example Hereinafter, one example of the present invention will be described in detail.

In FIG. 1, the output of an engine 10 provided in a vehicle is transmitted to a primary side rotating shaft 16 of a belt type continuously variable transmission 14 via a clutch 12.

The belt type continuously variable transmission 14 includes a primary-side rotating shaft 16 and a secondary-side rotating shaft 18, and the primary-side rotating shaft 16 and the secondary-side rotating shaft.
Variable primary side variable pulley mounted on 18 with variable effective diameter 20
And the secondary variable pulley 22 and those primary variable pulleys
20 and a transmission belt 24 wound around the secondary variable pulley 22 to transmit power, and a primary hydraulic cylinder for changing the effective diameters of the primary variable pulley 20 and the secondary variable pulley 22.
26 and a secondary hydraulic cylinder 28. The primary side hydraulic cylinder 26 and the secondary side hydraulic cylinder 28 are formed so as to have the same pressure receiving area, and the outer shapes of the primary side variable pulley 20 and the secondary side variable pulley 22 are the same and the belt type The speed change gear 14 is small. Then, the above-mentioned primary side variable pulley 20 and secondary side variable pulley 22
Is a fixed rotating body 31 and 32 fixed to the primary side rotating shaft 16 and the secondary side rotating shaft 18, respectively, and the primary side rotating shaft 16
And movable rotary bodies 34 and 36 which are provided on the secondary-side rotary shaft 18 so as not to be rotatable relative to each other and are movable in the axial direction and which form a V groove between the fixed rotary bodies 31 and 32.

The output from the secondary-side rotary shaft 18 of the belt type continuously variable transmission 14 is transmitted to the drive wheels of the vehicle through an auxiliary transmission, a differential gear device and the like (not shown).

The hydraulic control circuit for operating the power transmission device of the vehicle configured as described above is configured as described below. That is, the oil tank 38 is passed through a return path (not shown).
The hydraulic oil that has recirculated to is sucked by the oil pump 42 via the strainer 40 and the suction oil passage 41, and is pumped to the input port 46 of the speed change control valve device 44 and the first line oil passage 50 connected to the first pressure regulating valve 48. To be done. The oil pump 42 constitutes the hydraulic power source of this embodiment, and is driven by the engine 10 via a drive shaft (not shown). The first pressure regulating valve 48 is the first
According to the drive signal VD1, a part of the hydraulic oil in the first line oil passage 50 is made to flow out to the second line oil passage 52, whereby the first
Control the line hydraulic pressure Pl ₁ . The second line oil passage 52 is connected to the discharge port 54 of the shift control valve device 44 and the second pressure regulating valve 58, respectively. The second pressure regulating valve 58 causes a part of the hydraulic oil in the second line oil passage 52 to flow out to the drain oil passage 60 in accordance with a second drive signal VD2 which will be described later.
The second line oil pressure Pl ₂ which is relatively lower than the line oil pressure Pl ₁ is controlled. The first pressure regulating valve 48 and the second pressure regulating valve 58 are so-called electromagnetic proportional relief valves. In the present embodiment, the first line hydraulic pressure Pl ₁ is the hydraulic pressure of the high pressure side hydraulic source,
The second line hydraulic pressure Pl ₂ corresponds to the hydraulic pressure of the low pressure side hydraulic power source.

The shift control valve device 44 includes, in addition to the input port 46 and the discharge port 54, a pair of primary side hydraulic cylinder 26 and a secondary side hydraulic cylinder 28, which are connected via connection oil passages 29 and 30, respectively. It has a first output port 62 and a second output port 64, respectively. The shift control valve device 44
Is composed of a pair of direct-acting type first solenoid valve 66 and second solenoid valve 68 which are similarly configured. These first solenoid valves
Since the 66 and the second solenoid valve 68 have the same configuration as each other, the structure of the first solenoid valve 66 will be described below, and the same reference numerals are given to the respective portions of the second solenoid valve 68 and the description thereof will be omitted.

The first solenoid valve 66 includes a valve body 72 having a cylinder bore 70 formed therein, a spool valve 74 slidably fitted in the cylinder bore 70, and a core 76 fitted to one end of the spool valve 74. , A spring 80 for urging the spool valve element 74 in the axial direction to bring it into contact with the stopper member 78 to position it on the non-switching side, and the core 76 is attracted by the electromagnetic force to spool valve element 74.
An electromagnetic coil 82 is provided which is positioned on the switching side by driving 74 against the urging force of the spring 80. A first land 84, a second land 86, and a third land 88 are formed on the spool valve 74, and a first space between a first port 90 and a second port 92 provided on the valve body 72 is a first space. Land 84
The third land 94 and the fourth port 96 are opened and closed by the second land 86. The electromagnetic coil 82 and the core 76 form an electromagnetic solenoid, and the electromagnetic solenoid and the spring 80 form spool valve element driving means for driving and positioning the spool valve element 74.

The input port 46 is connected to the third port 94 of the first solenoid valve 66 and the second solenoid valve 68, respectively, and the discharge port
54 is connected to the second ports 92 of the first solenoid valve 66 and the second solenoid valve 68, respectively, and the first output port 62 is the fourth port 96 of the first solenoid valve 66 and the first port 90 of the second solenoid valve 68. And the second output port 64 is connected to the first solenoid valve 66.
The port 90 and the fourth port 96 of the second solenoid valve 68 are respectively connected.

Therefore, the shift control valve device 44 is in the neutral state, and the first solenoid valve 66
And each spool valve element 74 of the second solenoid valve 68 has a spring 80.
In the state where they are respectively brought into contact with the stopper members 78 according to the urging force of each of them and are prevented from moving in the axial direction to be respectively positioned on the non-switching side, the primary side hydraulic cylinder 26 and the secondary side hydraulic cylinder The 28, the first line oil passage 50, and the second line oil passage 52 are substantially cut off from each other. In this shut-off state, the gap forming a slight flow cross-sectional area for improving the output hydraulic pressure characteristic of the shift control valve device 44 is the primary side hydraulic cylinder 26, the secondary side hydraulic cylinder 28, and the first line oil passage. It may be provided between 50 and the second line oil passage 52.

In the first electromagnetic valve 66, the first speed ratio signal RA1 is supplied to the electromagnetic coil 82, so that the spool valve element 74 is driven against the urging force of the spring 80 and the first port 90 is operated.
And the second port 92, and the flow cross-sectional areas between the third port 94 and the fourth port 96 are changed. Therefore, the first
The line oil passage 50 and the primary hydraulic cylinder 26 are connected to each other, and the second line oil passage 52 and the secondary hydraulic cylinder 28 are connected to each other so that hydraulic oil flows into the primary hydraulic cylinder 26. Since the hydraulic oil in the secondary hydraulic cylinder 28 is caused to flow out, the speed ratio of the belt type continuously variable transmission 14 is changed in the increasing direction. That is, the first solenoid valve 66 changes the speed ratio of the belt type continuously variable transmission 14 exclusively in the increasing direction.

Also in the second electromagnetic valve 68, the second speed ratio signal RA2 is supplied to the electromagnetic coil 82, so that the spool valve element 74 is driven against the urging force of the spring 80 and the first port 90 is formed. The flow cross-sectional areas between the second port 92 and the third port 94 and the fourth port 96 are changed. Therefore, between the first line oil passage 50 and the secondary hydraulic cylinder 28,
Since the second line oil passage 52 and the primary hydraulic cylinder 26 are connected to each other, the hydraulic oil flows into the secondary hydraulic cylinder 28 and the hydraulic oil in the primary hydraulic cylinder 26 flows out. The speed ratio of the belt type continuously variable transmission 14 is changed in the decreasing direction. That is, the second solenoid valve 68 changes the speed ratio of the belt type continuously variable transmission 14 exclusively in the decreasing direction. In the figure, an annular groove 98 is formed on the outer periphery of the position where the ports 90, 92, 94, 96 of the valve body 72 are formed.

The belt type continuously variable transmission 14 has a first rotation sensor 100 for detecting the rotation speed N _in of the primary side rotation shaft 16 and a rotation speed N _out for the secondary side rotation shaft 18. Second
And the rotation sensor 102 is provided, the rotation signal SR2 from their first rotation sensor 100 and the second rotation sensor 102 representative of the rotation signal SP1 and the rotation speed N _out represents a rotational speed N _in is output to the controller 104. Further, the engine 10 is provided with a throttle sensor 106 for detecting a throttle valve opening degree θ _th provided in the intake pipe and an engine rotation sensor 108 for detecting an engine rotation speed N _e , The throttle sensor 106 and the engine rotation sensor 108 output a throttle signal Sθ indicating the throttle valve opening θ _th and a rotation signal SE indicating the engine rotation speed N _e to the controller 104.

The controller 104 is a so-called microcomputer including a CPU 112, a ROM 114, a RAM 116, etc., and constitutes the control means of this embodiment. The CPU 112 processes the input signal according to the program stored in advance in the ROM 114 while using the storage function of the RAM 116, and controls the first line hydraulic pressure and the second line hydraulic pressure by the first pressure regulating valve 48 and the second pressure regulating valve. At the same time as supplying the first drive signal VD1 and the second drive signal VD2 to the pressure valve 58, a first speed ratio signal RA1 for operating the first solenoid valve 66 and the second solenoid valve 68 to control the speed ratio e. And a second speed ratio signal RA2 to them.

The speed ratio control of the belt type continuously variable transmission 14 is performed by, for example, the second
This is performed by repeatedly executing the speed ratio control routine shown in the figure. That is, first, by executing step S1, the rotational speed N _in of the primary rotary shaft 16, the rotational speed N _out of the secondary rotary shaft 18, the throttle valve opening θ _th , and the engine rotational speed _Ne are rotated. It is read into the RAM 116 based on the signals SR1 and SR2, the throttle signal Sθ, and the rotation signal SE. Next, in step S2, the speed ratio e is calculated from the rotational speeds N _in and N _out according to the following equation (1) stored in the ROM 114 in advance.

e = N _out / N _in (1) Further, in step S3, the target rotation speed N _in ^* is determined based on the throttle valve opening θ _{th and the} like from the relationship stored in the ROM 114, and (1) above. From the equation, the target speed ratio e ^* is calculated from the target rotation speed N _in ^* and the actual rotation speed N _out . The relationship for determining the target rotation speed N _in ^* is, for example, as shown in FIG. 3, and is obtained in advance so that the engine 10 operates exclusively on the minimum fuel consumption rate curve shown in FIG. Is. In the following step S4, the speed ratio control value V ₀ is calculated according to the following equation (2) stored in the ROM 104 in advance. In step S5 described later, this speed ratio control value V ₀
Is positive, the spool valve element 74 of the first solenoid valve 66 is moved against the urging force of the spring 80 so that the rotation speed N _in of the primary side rotating shaft 16 decreases. When the speed ratio signal RA1 is output and is negative on the contrary, the spool valve element 74 of the second solenoid valve 68 is driven to drive the primary side rotary shaft.
The second speed ratio signal R so that the rotation speed N _{in of} 16 increases.
A2 is output. The first speed ratio signal RA1 and the second speed ratio signal RA1
The magnitude of the speed ratio signal RA2 corresponds to the magnitude of the speed ratio control value V ₀ , that is, the movement amount of the spool valve element 74. Therefore, as is apparent from the following equation (2), the speed ratio control value V ₀ is determined so as to match the actual speed ratio e and the target speed ratio e ^* . Note that k in the equation (2) is a control constant.

V ₀ = k (e ^* −e) / e (2) Then, in step S5, the first speed ratio signal is output according to the speed ratio control value V ₀ determined in the previous step.
RA1 and the second speed ratio signal RA2 are output, and the speed ratio e is controlled.

Here, as described above, in the shift control valve device 44,
The springs 80 of the first electromagnetic valve 66 and the second electromagnetic valve 68 bring the pair of spool valve elements 74 into contact with the stopper member 78 at a fixed position to prevent the axial movement thereof, whereby the shift control valve. The operating state of the device is set to the neutral state. Therefore, compared to the conventional shift control valve of the type in which the flow direction of hydraulic fluid is controlled by driving a single spool valve element through a link that is mechanically connected, there is less tolerance for parts. The variation in the neutral point of the shift control valve caused by the variation is eliminated, and the work of adjusting the neutral point setting is unnecessary at the time of assembling the hydraulic control device. In addition, compared to a shift control valve in which a spool valve element is biased in opposite directions by a pair of springs, and the spool valve element is positioned at a neutral point where the biasing forces are balanced, foreign matter and sliding The deviation of the neutral point of the spool valve due to the change of dynamic friction is almost eliminated.

Further, in the shift control valve device 44 of the present embodiment, since it is configured by providing a pair of spool valve elements 74, compared with the conventional case using a single spool valve element 74 and spool valve element 74 The cylinder bore 70 can be easily machined, the number of parts is small, the structure is simple, and the device is small.

Further, in this embodiment, since the spool valve element 74 is a direct drive type that is directly driven, there is an advantage that it operates more stably against foreign matter in the hydraulic oil and changes in sliding frictional force.

Next, another embodiment of the present invention will be described. In the following embodiments, the parts having the same functions are designated by the same reference numerals and the description thereof will be omitted.

In the above-described embodiment, the spool valve element 74 is directly driven by the electromagnetic solenoid including the electromagnetic coil 82 and the core 76, but it may be slid by hydraulic pressure as shown in FIG. That is, in the shift control valve device 44,
The first solenoid valve 66 and the second solenoid valve which are constructed in the same manner as each other
A first spool valve 120 having a control function similar to that of the solenoid valve 68.
And a second spool valve 122 is provided. The first spool valve 120 and the second spool valve 122 are provided in the same oil passage as the shift control valve device 44 formed in the cylinder body 72, and the spool valve element 74 of the first spool valve 120 is provided. The speed ratio is exclusively increased by moving in the cylinder bore 70 in the direction against the biasing force of the spring 80, and the spool valve 74 of the second spool valve 122 resists the biasing force of the spring 80 in the cylinder bore 70. By being moved in the direction, the speed ratio is exclusively reduced. Therefore, in the neutral state of the shift control valve 44, the spool valve element 74 of the first spool valve 120 and the spool valve element 74 of the second spool valve 122 are moved according to the urging force of the spring 80, and one end of the cylinder bore 70 is moved. Since the shift control valve device 44 is brought into a neutral state by being brought into contact with the inner wall portion 124, the same effect as that of the above-described embodiment can be obtained. The inner wall surface 124 at one end of the cylinder bore 70 with which the spool valve element 74 abuts functions as a stopper.

A pressure reducing valve 126 is provided between the second line oil passage 52 and the drain oil passage 60.
And the throttle 128 are connected in series, and the pilot hydraulic pressure is generated between the pressure reducing valve 126 and the throttle 128. This pilot hydraulic pressure is
The end faces of the spool valve element 74 of the first spool valve 120 and the spool valve element 74 of the second spool valve 122 on the side of the inner wall surface 124 are acted on via the. The pilot hydraulic pressure is also applied to the end faces of the spool valve element 74 of the first spool valve 120 and the spool valve element 74 of the second spool valve 122 on the spring 80 side via the throttles 132 and 134. Then, between the throttle 132 and the first spool valve 120, and between the throttle
Between the 134 and the second spool valve 122, the downstream side of the throttle 132 is drained, that is, opened to the atmosphere and the spool valve 74
For moving the spring against the biasing force of the spring 80
A pilot solenoid on-off valve 136 and a second pilot solenoid on-off valve 138 are provided. Therefore, in the state where the first pilot solenoid on-off valve 136 and the second pilot solenoid on-off valve 138 are closed, as described above, the spool valve element 74 of the first spool valve 120 and the second spool valve 122.
The spool valve elements 74 are moved according to the urging force of the spring 80 and brought into contact with the inner wall surface 124 of the one end portion of the cylinder bore 70, whereby the shift control valve device 44
Is in a neutral state.

However, when the first pilot solenoid on-off valve 136 is opened, the speed ratio of the belt type continuously variable transmission 14 is changed in the increasing direction, and when the second pilot solenoid on-off valve 138 is opened, the belt type continuously variable transmission. The speed ratio of 14 is changed in the decreasing direction. Normally, the speed ratio signals RA1 and RA2 supplied to the first pilot solenoid opening / closing valve 136 and the second pilot solenoid opening / closing valve 138 are ON / OFF signals, and the first pilot solenoid opening / closing valve 136 and the second pilot solenoid opening / closing valve 136 are used. Although the electromagnetic on-off valve 138 is duty-controlled, the hydraulic pressure applied to the end surface of the spool valve element 74 on the spring 80 side and the position of the spool valve element 74 whose position is controlled by this hydraulic pressure are continuously changed.

Although the embodiment of the present invention has been described above with reference to the drawings, the present invention can be applied to other aspects.

For example, in the speed change control valve 44 of the embodiment shown in FIG. 1, the spool 80 is driven by the spring 80 and the electromagnetic solenoid, but it is constituted by a pair of electromagnetic solenoids that drive the spool valve in opposite directions. May be.

Further, in the shift control valve 44 of the embodiment shown in FIG. 5, the inner wall surface 124 side of the spool valve element 74 is opened to the atmospheric pressure, and the spring 80 is provided on the inner wall surface 124 side of the spool valve element 74 so that the spool valve element 74 is opposed thereto. You may make it urge toward a direction. In this case, the operational relationship between the pilot solenoid on-off valves 136 and 138 and the spool valves 120 and 122 is reversed.

Further, in the embodiment of FIG. 1, the speed ratio signals RA1 and RA2 supplied to the first electromagnetic valve 66 and the second electromagnetic valve 68 of the shift control valve device 44 are continuously changed,
Therefore, the first solenoid valve 66 and the second solenoid valve 68 were proportionally controlled, but the speed ratio signals RA1 and RA2 were turned on / off signals, and the first solenoid valve 66 and the second solenoid valve 68 were used.
May be duty controlled.

The above description is merely an example of the present invention, and the present invention can be variously modified without departing from the spirit thereof.

[Brief description of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention. Second
The figure is a flow chart for explaining the shift control operation in the apparatus of FIG. FIG. 3 is a diagram showing a relation used in the explanation of FIG. 2 and for obtaining a target rotation speed. FIG. 4 is a diagram showing a minimum fuel consumption rate curve of the engine of FIG. FIG. 5 is a view showing the essential parts of another embodiment of the present invention. 14: Belt type continuously variable transmission 16: Primary side rotating shaft, 18: Secondary side rotating shaft 20: Primary side variable pulley 22: Secondary side variable pulley 24: Transmission belt 26: Primary side hydraulic cylinder 28: Secondary side Hydraulic cylinder 44: Shift control valve device 72: Valve body, 70: Cylinder bore 74: Spool valve, 78: Stopper member 80: Spring 124: Inner wall surface (stopper)

Front Page Continuation (72) Inventor Yoshinobu Soga 1 Toyota Town, Toyota City, Aichi Prefecture, Toyota Motor Corporation (56) References JP 57-90450 (JP, A) JP 62-31761 (JP, A) JP-A-56-46152 (JP, A)

Claims (1)

[Claims] 1. A pair of primary side variable pulley and secondary side variable pulley respectively provided on a primary side rotating shaft and a secondary side rotating shaft, and a transmission belt which is wound around the pair of variable pulleys to transmit power. And a pair of primary-side hydraulic cylinders and a secondary-side hydraulic cylinder that change the effective diameters of the pair of variable pulleys, respectively. The effective diameter of the primary variable pulley and the secondary variable pulley is changed by supplying hydraulic oil to one of the primary hydraulic cylinder and the secondary hydraulic cylinder, and at the same time allowing hydraulic oil in the other to flow out. A hydraulic control device comprising a shift control valve device for adjusting the speed ratio of the continuously variable transmission, wherein the shift control valve device is a pair of cylinder bores formed in a valve body. And a pair of spool valve elements that are slidably fitted in the cylinder bores and are brought into contact with stoppers so that they are respectively positioned on the non-switching side and make the operation of the shift control valve device in a neutral state. , A pair of spool valves that respectively control the supply of hydraulic oil to the one hydraulic cylinder and the outflow of hydraulic oil from the other hydraulic cylinder by driving the spool valve element from the non-switching side to the switching side. Child drive means, and one of the pair of spool valve elements supplies hydraulic oil to the primary hydraulic cylinder and discharges hydraulic oil from the secondary hydraulic cylinder on its switching side. The speed ratio is exclusively changed in the increasing direction, and the other of the pair of spool valve elements supplies hydraulic oil to the secondary hydraulic cylinder on the switching side thereof. A hydraulic control device for a belt-type continuously variable transmission for a vehicle, which is characterized in that the speed ratio is exclusively changed by discharging hydraulic oil in the primary side hydraulic cylinder.