JPH0289851A - Hydraulic control device for continuously variable transmission - Google Patents

Abstract

PURPOSE:To enable effective utilization of a space by a method wherein a solenoid valve is fastened on a valve block and situated in an empty space between a continuously variable speed change gear case and a pulley, and a drain port is formed in a state to be exposed in a horizontal state from an oil level. CONSTITUTION:A solenoid valve 97 for switching a line pressure in a 2-stage is fastened against a valve block 150 and is mounted in an empty space formed between a continuously variable speed change gear case 7 and a pulley 36. The drain port 97a of the solenoid valve 97 is formed in a manner to be horizontally exposed from an oil level. Since the drain port 97a of the solenoid valve 97 is horizontally exposed from an oil level and no back pressure is exerted thereon, drain is executed with normally excellent response to perform a switching motion. This constitution compacts a mounting space, always improves response, and enables improvement of assembling ability and facilitation of confirmation of a function.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a hydraulic control device for a belt type continuously variable transmission for a vehicle, and more particularly to a solenoid valve arrangement structure when a solenoid valve with a drain boat is provided in a hydraulic control system.

[Conventional technology]

Conventionally, hydraulic control systems for continuously variable transmissions have been developed, for example, by
As shown in Japanese Patent No. 157930, the configuration is based on controlling the line pressure using a line pressure regulating valve and controlling the speed change using a gear ratio control valve.

[Problem to be solved by the invention]

By the way, the above-mentioned prior art has the minimum number of valves (8 valves), and therefore the line pressure and gear change are controlled with the minimum necessary characteristics.However, in reality, line pressure control is dependent on the transmission torque. Therefore, it is necessary to adjust the speed change control to match the driving feeling, and for this purpose, various other means and valves are added.Here, the hydraulic control system is equipped with electrical signals to perform switching operations or control hydraulic pressure. In some cases, a solenoid valve with a drain boat is installed, which causes a problem with the installation location due to the large size of the solenoid valve.Furthermore, if the drain port is placed above the oil level, the back of the drain port may be damaged, especially at low temperatures. Drainage is restricted due to pressure, which leads to deterioration of response.For this reason, it is desirable to consider the installation location of such a solenoid valve.The present invention has been made in view of this point. The purpose of this is to improve the hydraulic control system of a continuously variable transmission, which can optimize the placement of the solenoid valve by making effective use of space when a solenoid valve with a drain port is installed in the hydraulic control system. Our goal is to provide the following.

[Means for Solving the Problems] In order to configure the above V1 objective, the hydraulic control device of the present invention includes:
In a continuously variable transmission having a solenoid valve with drain bow 1 in the hydraulic control system, the solenoid valve is fastened on the valve block and installed in the empty space created between the continuously variable transmission case and the pulley, The drain boat of the solenoid valve is installed so as to be exposed above the oil surface at least horizontally. [Operation] Also based on the 14 configuration, the relatively large solenoid valve of the hydraulic control system of the continuously variable transmission is compactly arranged in the open space around the pulley while being attached to the valve block. Since the drain port 1 of the solenoid valve is exposed horizontally on the oil surface and does not receive back pressure, it can drain with good response and perform switching operations, etc.

【Example】

Embodiments of the present invention will be specifically described below based on the drawings. Referring to FIG. 1, a belt-type continuously variable transmission based on a front engine φ front drive (FF) and a transverse transaxle type combined with an electromagnetic powder clutch will be described. The symbol 1 is an electromagnetic powder type clutch, 2 is a forward/reverse switching device, 3 is a continuously variable transmission, and 4 is a freon I/differential device. An electromagnetic powder type clutch l is housed in one side of the clutch housing 6, and the other side of the clutch housing 6, a main case 7 joined thereto, and a side case joined to the side opposite to the clutch housing 6 of the main case 7. 8 has a forward/reverse switching device 2. Continuously variable transmission 3. A front differential device 4 is housed therein. The electromagnetic powder clutch l includes a ring-shaped drive member 12. which is integrally connected to the engine crankshaft IO via a drive plate 11. A disk-shaped driven member I that is integrally spline-coupled to the transmission input shaft 13 in the rotational direction.
It has 4. A coil 15 is built into the outer peripheral side of the driven member 14, and a gap 1G is formed along the circumference between the two members 12 and 14, and this gap 16 contains electromagnetic powder. In addition, a power supply brush 19 is in sliding contact with a slip ring I8 of the hub portion of the driven member 14 equipped with a coil 15, and is further connected to the coil 15 through the inside of the driven member 14 from the slip ring 18 to form a clutch current circuit. ing. In this way, when a clutch current is applied to the coil 15, the drive and driven member 12.1 are connected through the gap 1G.
Due to the lines of magnetic force generated between 4 and 4, electromagnetic particles are combined and accumulated in a chain in the gap 1G, resulting in j! The driven member 14 is integrally connected to the total force drive member I2 while sliding, and the clutch is connected. On the other hand, when the clutch current is cut, the drive and driven member due to electromagnetic powder

[2゜14 coupling force is lost and the clutch becomes disconnected. If the clutch current in this case is controlled in conjunction with the operation of the forward/reverse switching device 2, it is possible to move from P (parking) or N to neutral) to forward D (drive), Ds<sporty drive). or R of retreat (
Clutch 1 is automatically connected and disconnected when switching to the reverse (reverse) range, eliminating the need for clutch pedal operation. Next, the forward/reverse switching device 2 includes a human power shaft 13 from the clutch I and a primary shaft 20 disposed coaxially therewith.
established between. That is, a reverse drive gear 2I that also serves as a forward wave engagement side is formed on the human power shaft 13, and a reverse drive engaged side gear 22 is rotatably fitted to the primary shaft 20. 21 and 22 are counter gears 24 supported by a shaft 23. They are meshed through an idler gear 26 supported by a shaft 25. A switching mechanism 27 is provided between the primary shaft 20 and the gears 21 and 22.
is provided. The above gear 2+, which is always in mesh here,
24, 26, and 22 are connected to the driven member I4 having the coil 15 of the clutch l, and corresponding to the fact that the inertia mass of this part is relatively large when the clutch is disengaged, the switching mechanism 27 is connected to the driven member I4 having the coil 15 of the clutch l. The sleeve 29 spline-fitted to the hub 28 is connected to the synchronizer 411; 30.3.
1 to be meshed and connected to each gear 21 and 22. As a result, in the neutral position of the P or N range, the sleeve 29 of the switching mechanism 27 is fitted only with the hub 28, and the primary shaft 20 is separated from the manual Idl 13. Next, when the sleeve 29 is engaged with the gear 2I via the synchronizing mechanism 30, the primary shaft 20 is directly connected to the input shaft 13, resulting in a forward movement state in the D or Ds range. On the other hand, when the sleeve 29 is conversely engaged with the gear 22 side via the synchronizing mechanism 31, the input Idl13 is
It is connected to the primary shaft 20 through 24, 28, and 22, and the engine power is decelerated and reversed to enter the R range reverse state. In the continuously variable transmission Ja3, a secondary shaft 35 is arranged parallel to the primary shaft 20, and primary pulleys 36. Secondary pulley 37
An endless drive belt 34 is provided between both pulleys 3G and 37. Primary pulley 36. The secondary pulleys 37 are each divided into two parts, and one of the fixed pulleys 36a and 37a is movable, while the other movable pulley 3 (ib, 371) is movable to make the pulley interval variable, and the movable pulleys Hb and 37b are movable. for,
Hydraulic servo device 3g, which itself doubles as a piston, 39
is attached to the movable pulley 3 of the secondary pulley 37.
7b, a spring 40 is installed in the direction to narrow the pulley interval.
is energized. Further, as a hydraulic control system, an oil pump 41 as an operating source is installed next to the primary pulley 36. This oil pump 41 is a high-pressure gear pump, and the pump drive shaft 42 is connected to the primary pulley 36. It penetrates the inside of the primary shaft 20 and the input shaft 13 and is directly connected to the crankshaft IO, so that hydraulic pressure is constantly generated during engine operation. Then, the hydraulic pressure of the oil pump 41 is controlled to supply and drain oil to each hydraulic servo device q3g and 39, and the pulley spacing between the primary pulley 36 and the secondary pulley 37 is changed to an inverse relationship, so that the pulley 3B of the drive belt 34 , 37 are converted steplessly, and steplessly variable power is output to the secondary shaft 35. In view of the fact that the minimum pulley ratio on the high speed side of the continuously variable transmission 3 is very small, for example 0.5, and therefore the rotational speed of the secondary shaft 35 is high, the front differential device 4 has a An output shaft 44 is connected via a pair of intermediate reduction gears 43a and 43b. The final gear 4G meshes with the drive gear 45 of the output shaft 44, and the final gear 46 transmits power (Δ) to the left and right front wheel axles 48a, 48b via the differential mechanism 47. To explain the hydraulic control system of the continuously variable transmission 3, in the primary hydraulic servo device 38, a movable pulley 36b is fitted into a cylinder 38a that is integrated with the primary shaft 20, and the primary control system is controlled by supplying and draining oil into the cylinder Ha. Also in the secondary hydraulic servo device 39, the movable pulley 37b is fitted into the cylinder 39a which is integrated with the secondary f11135, and line pressure is introduced into the cylinder 39a. Pulley 3
6b has a larger pressure receiving area and enables speed change control using only the primary pressure. The oil pumped up from the oil reservoir 70 by the oil pump 41 is passed through the oil passage 71a to the line pressure regulating valve 90.
A line pressure oil passage 71 that is guided by the oil passage 71a and branches from the oil passage 71a.
b constantly communicates line pressure to the secondary cylinder 39a. A passage 71c branching from the oil passage 71a communicates with a gear ratio control valve 100, and this gear ratio! +J goben 1
An oil passage 72 communicates between the primer cylinder 38a and the primer cylinder 38a. Further, a pitot pressure sensor 73 is located at the primary cylinder 38a to obtain a pitot pressure as a control pressure according to the engine speed during shift control after clutch engagement.
is installed, and the pitot pressure from this pitot pressure sensor 73 is transmitted via an oil passage 74 to a line pressure regulating valve 90. The transmission ratio control valve 100 is asked. Furthermore, in contrast to the D range, which performs shift control over a wide range including low engine speeds, the Ds range performs shift control only in a high engine speed range, and applies engine braking when the accelerator is released. As a hydraulic system that obtains line pressure, i! l! Drain oil path 75a from l valve 90
An oil passage 75b of the riverside hydraulic circuit that branches from the upstream side of the relief valve 76 communicates with the select position detection valve 130, and an oil passage 75c that further branches from the passage 75b controls the transmission ratio. It communicates with the engine brake actuator 140 of the control valve 100. Oil passage 75d branching from oil passage 75a of the lubrication hydraulic circuit
is the belt nozzle 7 arranged on the inner circumference of the belt 34.
7, the oil passage 75c communicates with the oil supply lower 8 of the pitot pressure sensor 73, and the oil passage 750 communicates with the oil reservoir 70 via the check valve 79° oil cooler 80. A balancer chamber 3 is located on the opposite side of the hydraulic chamber 39b of the secondary cylinder 39a.
9c is provided, and the outlet side oil passage 81 of the oil cooler 80 communicates with the balancer chamber 39e and fills it with oil.
The centrifugal oil pressure of 9b is offset by balancer chamber 3'llc. Further, a shift lock valve 84 equipped with a check valve 83 is provided in the middle of the drain oil passage 82 of the gear ratio control valve 100, and a pre-feeling valve 84 is provided between the passage 82 upstream of the check valve 83 and the passage 75b. Passage 85
is connected. It should be noted that an orifice 8G is provided at one end of each passageway. The line pressure 1/3 regulating valve 90 has a valve body 91. Spool 92
゜It has a spring 94 which is biased between the bush 93 on one side of the spool 92 and the primary movable pulley 3.
Sensor shoe 9 that engages with Gb and detects the actual gear ratio
5 is movably supported by a tube 96 arranged with lubrication passages and connected to a bush 93. In the valve body 91, the pitot pressure of the oil passage 74 acts on the boat 91a on the opposite side of the spring 94 of the spool 92, and the passage 7 is applied to the boat 91c adjacent to the boat 9Ja via the drain boat 91b.
The line pressure of La acts. In addition, a boat 91d to which line pressure is introduced and a drain port 9 adjacent to the boat 91c.
1c, and has a land chamfer portion 92 of the spool 92.
Drain boat 91.a is used to adjust the pressure by changing the drain pressure. A two-stage line pressure switching port 91r is provided on the spring 94 side adjacent to a. On the other hand, a line pressure oil passage 'He is provided with a line pressure two-stage switching solenoid valve 97. This two-stage line pressure switching solenoid valve 97 is a three-way valve that selectively communicates the passage 98 connected to the two-stage line pressure switching boat 91f' with the passage 71c side and the drain side, and when energized, Passage 71c and 98 are connected to form line pressure two-stage switching port 9.
Line pressure was applied to 11' by j47, and Ura v698 due to de-energization.
This is a depiction of draining. In this way, the spring force of the spring 94 of the spool 92 increases as the gear ratio increases, and this spring force acts on the line pressure increasing side. Further, the line pressures of the boat 91c and the line pressure two-stage switching boat 91f' act on the line pressure decreasing side, and the line pressure is controlled by the balance between these two. The pitot pressure at the end of the spool 92 acts to adjust the balance point of the spool 92 as the pump displacement changes with engine speed. Therefore, the spring force F at the balance point of the spring 94 is
, line pressure PL, and the pressure receiving area difference between the boat 91c and the line pressure two-stage switching port 91f as AL and Ac, and when the line pressure two-stage switching solenoid valve 97 is de-energized, A I, ψPL-F are When established, the line pressure is controlled at high pressure by PL-F/AL. Furthermore, when the line pressure two-stage switching solenoid valve 97 is energized, (AL+Ac)・PI, -F is established, and the line pressure is PL -F/(AL +Aa).
Controlled by low pressure. In this way, the line pressure is steplessly controlled by the spring force that changes according to the transmission ratio, and the line pressure level is controlled in two stages, low and high, by the two-stage line pressure switching solenoid valve 97, which pushes the pulley. It begins to generate power. The gear ratio control valve 100 has a spool lO'2 on one side of the valve body 101, and a boat 101 at one end of the spool 102.
A shows pitot pressure at check valve 103 or orifice 1.
04, and a low speed spring 105. High speed spring 106 is biased. In addition, the boat 10lb in the center of the spool 102 is connected to the oil passage 7.
2, the left and right ports 101c and 101d are drain oil passages 82. It communicates with the line pressure oil passage 71c, and the spool 10
The primary cylinder 38a is supplied with and drained from the primary cylinder 38a by the groove portion 102a of the second cylinder 38a to generate primary pressure. The other side of the valve body 101 has a plunger 107, and one end of the rod 10B is attached to the plunger 107 with a spring 1.
09 and roller 1 at the other end of the rod 108.
Shift cam +1 that rotates according to the accelerator opening on 08a
0 comes into sliding contact. A guide 111 is attached to the plunger 107 and receives the spring 105, thus changing the force of the spring 105 in accordance with the rotation of the shift cam 110. Here, the plunger 107 has an oil passage 74.
The pitot pressure is guided, and the spring reaction force acting on the plunger 107 is received by the pitot pressure, and the shift cam 11
It is designed to reduce the operating force of 1. Additionally, a mechanical modulator mechanism 120 is provided between plunger 107 and spring 10B. This modulator mechanism 120 has a variable mechanism 121 between the plunger 107 and a spring receiver 112 inside the guide 111, and this variable mechanism 121 is connected to the sensor shoe 95 via a link 122. The variable mechanism 121 acts as a modulator to gradually increase the force of the spring 106 as the gear ratio shifts to a high speed gear. In this way, the spool 102 has the pitot pressure and the shift cam 1
The force of the spring 105 is applied according to the accelerator opening degree. A predetermined primary pressure is generated by the balance between the two to determine the gear ratio, and the gear ratio is controlled to upshift to a high speed gear as the pitot pressure increases with the increase in vehicle speed. At this time, the modulator mechanism 120 further applies a force of the spring 106 in accordance with the gear ratio to the spool 102, thereby gradually increasing the engine speed in accordance with the upshift to the high speed gear. In the select position detection valve 130, a valve body 133 having a drain hole 132 is inserted into a valve body 131, and a cam 13 that rotates in accordance with the operation of a select lever 13B is inserted into the valve body 133.
5 is the contact. Here, in the cam 135, D, N
, R range position is the convex portion 135a, and P and D at both ends
The range position of s is in the recess 135b, and as described above,
Drain holes 132 are opened in each of the N and R ranges to generate operating oil pressure. Furthermore, when the P and Ds cylinder drain holes 132 are opened, the orifice 86 prevents the oil pressure in the upstream oil passage 75a from decreasing. The engine brake actuator 140 has a piston 142 inserted into a cylinder 141.
A return spring 143 is attached to one side of 2),
The operating oil pressure of the oil passage 756 is exclusively supplied to the other piston chamber 144 via the oil passage 75c. Also, the hook 142a at the tip of the piston 142, the rod 10 of the gear ratio control valve 100,
A lever 146 of a modifying mechanism 145 for correcting the Ds range characteristic, which also serves as a push lever, is provided between the roller pin 108b and the sensor shoe 95 in an engaging manner. In this way, when there is no hydraulic pressure for operating the P and Ds cylinders, the lever 14G is swung by the hook 142a of the piston 142, and the rod 108 is forcibly pushed in a predetermined stroke, thereby limiting the shift range to the high engine speed side. This causes the Ds cylinder engine brake to act. When a predetermined gear ratio is reached in this state, the sensor shoe 95 engages with the lever 14G, and from this point forward, the sensor shoe 95 swings the lever 14G in the opposite direction as the gear ratio increases, and the piston 142, The rods 108 are sequentially pulled back to the light position. In the drawings after FIG. 3, each valve arrangement structure will be described. First, as shown in FIG. 3, inside the main case 7 of the continuously variable transmission Ja3, the primary shaft 20 is disposed downward, the secondary shaft 35 is disposed obliquely upward, and the primary shaft 20 is disposed diagonally upward. 120. Primary pulley 36 of secondary shaft 35. The belt 34 is wound around the secondary pulley 37 at an angle. Further, an oil pan 70a forming an oil reservoir 70 is attached to an opening 7a of the main case 7 directly below the primary pulley 36.
The valve block 150 is housed and installed at an angle inside the valve block 150. The valve block 150 has a line pressure control well 90 for a hydraulic control system inside a body 151 having a predetermined shape as shown in FIGS. 4(a) and 4(b). Gear ratio control well 100. Engine brake actuators 140 etc. are arranged and installed,
Furthermore, six oil passages 71a, 71c, etc. are provided. Further, the upper part of the body 151 is opened and a plate 152 is attached thereto to seal it. and primary pulley 3G
a sensor shoe 95 whose one end engages with the movable pulley 36b of the sensor shoe 95;
is connected to the line pressure one-turn regulating valve 90 side of the body 151. Thus, in the above arrangement, a relatively large space is left adjacent to the sensor shoe 95 between the primary pulley 36 and the valve block 150 below. Therefore, the line pressure two-stage switching solenoid valve 97 is mounted on the plate 152 of the valve block 150 at a location that corresponds to the above-mentioned empty space. That is, plate 15
Circuit block 15 which connects oil passages 71c and 98 on 2
3 is erected and fastened with bolts 154, and a bracket 155 is attached to this circuit block 153 with bolts 154.
By fixing, the line pressure two-stage switching solenoid valve 97 is installed horizontally with the drain port 97a facing outward. As a result, the line pressure two-stage switching solenoid valve 97
is installed in the open space below the primary pulley 36 alongside the sensor shoe 95, and the solenoid valve 97 is installed along with the sensor shoe 95.
By projecting horizontally above the valve block 150, the drain port 1-97a is horizontally exposed and opened above the oil surface. Next, the operation of the continuously variable transmission control system configured as described above will be explained. First, before the vehicle stops or starts shifting at the start of running, the line pressure regulated by the line pressure regulating valve 90 is zero only in the secondary cylinder 39a through the oil passage 71b, and the primary cylinder 38a is connected to the gear ratio control valve. 100 communicates with the drain oil passage 82. Therefore, in the continuously variable transmission 3, the diameter of the winding of the secondary pulley 37 with respect to the primary pulley 3G of the drive belt 34 is the largest, and the maximum gear ratio is 1.
1. becomes the low gear. Next, after driving, the pitot pressure of the pitot pressure sensor 73 increases and moves the spool 102 of the gear ratio control valve 100, and when the line pressure of the oil passage 71e is supplied to the primary cylinder 38a via the oil passage 72, the prefill The action immediately generates primary pressure and starts upshifting. As the primary pressure increases, the diameter of the winding of the drive belt 34 around the primary pulley 3G increases, and finally the speed is continuously variable to the high speed stage with the minimum gear ratio 'I+. On the other hand, in the above-mentioned stepless barley speed control, when the line pressure two-stage switching solenoid valve 97 is energized during steady running at low and medium angles 6:f, the line pressure two-stage switching port 91 of the line pressure regulating valve 90 is The line pressure is switched to be introduced through the oil passage 98.The line pressure regulating valve 90 is then switched to the boat 91c.
The pressure is regulated by the balance between the line pressure of the two-stage line pressure switching port 91 and the spring force of the sensor shoe 95 according to the gear ratio.
As shown in the figure, the characteristics change depending on the gear ratio at low pressure levels. Next, when the line pressure two-stage switching solenoid valve 97 is de-energized during running under high load, etc., the hydraulic pressure in the line pressure two-stage switching port 91' is switched to drain through the drain port 97a. Pressure jl'J In the regulating valve 90, the spool 92 shifts to the high pressure side, and the line pressure becomes a high pressure level characteristic as shown by the curve pLh in FIG.
Through the switching operation, the line pressure is controlled to two low levels and two stages, and an appropriate pulley pressing force is applied under each power transmission condition without causing excessive pulley pressing force, friction loss, belt slip, etc. Become. In addition, the line pressure two-stage switching solenoid valve 97 has the drain port 97a exposed horizontally above the oil surface, so that it does not receive back pressure from the oil sump oil when switching to the drain side. Therefore, the drain is always quickly drained from the drain port 97a.
Switches to the drain side with good response. Although the embodiments of the present invention have been described above, the present invention can also be applied to solenoid valves that generate control oil pressure based on duty signals. Effects of the Invention As described above, according to the present invention, when a solenoid valve with a drain port is provided in the hydraulic control system of a continuously variable transmission, the solenoid valve is located in the opening space below the circular pulley. The arrangement allows for a compact installation. The solenoid valve's drain boat is exposed horizontally above the oil surface, ensuring good responsiveness at all times. Since the solenoid valve is installed in the valve block, it is easy to assemble and it is easy to check its function.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an example of a continuously variable transmission to which the present invention is applied, Fig. 2 is a circuit diagram showing an embodiment of the hydraulic control device of the present invention, and Fig. 3 is a rear view showing the valve block installed state. 4(a) is a side view of the valve block, FIG. 4(b) is a perspective view thereof, and FIG. 5 is a characteristic diagram of line pressure. 3...Continuously variable transmission, 7...Main case, 36...
・Primary pulley, 70a...Oil pan, 97・
...Solenoid valve for line pressure two-stage switching, 97a...Drain boat, ...Valve block, ...Mounted with bracket.

Claims (1)

[Claims] In a hydraulic control system of a continuously variable transmission having a solenoid valve with a drain port, the solenoid valve is fastened onto a valve block and a gap is created between the continuously variable transmission case and the pulley. A hydraulic control device for a continuously variable transmission, which is installed in a space so that the drain port of the solenoid valve is exposed above an oil surface at least in a horizontal state.