JPH07286659A - Belt type continuously variable transmission - Google Patents

Abstract

PURPOSE:To detect oil temperature and oil quantity of working oil by means of a simple and inexpensive constitution. CONSTITUTION:A belt type continuously variable transmission is provided with a belt 61, transmission pulleys 5, 7, a spring 63 applying tension to the belt 61, a hydraulic actuator which receives a working oil pressure so as to move a flange 29 for changing a speed change ratio, an oil pump 79 which pressurizes oil in an oil source 81 for generating the working oil pressure, a controlling valve 77 controlling the working oil pressure, a resistor for current detection, respective required devices indicating oil quantity and an abnormal condition in an oil cooling system, and a controller 83 which detects respective abnormal conditions on the basis of a change in electric current in the resistor and the oil pressure for operating the respective required devices.

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.

[0002]

2. Description of the Related Art JP-A-64-46056 discloses a belt type continuously variable transmission 201 as shown in FIG. This is configured such that a pair of speed change pulleys 203 and 205 are connected by a belt 207, and a movable flange 209 of the speed change pulley 203 is moved to a fixed flange 213 side by a hydraulic actuator 211 to control a speed change ratio. The operating oil pressure of the hydraulic actuator 211 is created by pressurizing the engine oil with an oil pump driven by the engine.

[0003]

Conventionally, in order to detect the amount of hydraulic oil, oil level sensors 215, 217 and 219 as shown in FIGS. 6, 7 and 8 (published by the Society of Automotive Engineers of Japan)
Automotive Technology Handbook, Design Edition, P107, 108) and the like are used. Oil level sensor 215
Uses the change in the amount of heat radiation of the resistance wire 221 due to the change in the oil level, the oil level sensor 217 detects the oil level by the float 223 with a built-in contact, and the oil level sensor 219 by the float 227 with a built-in magnet 225. Turn reed switch 229 ON-O
FF is performed to detect the oil level. All of these oil level sensors 215, 217, 219 are expensive, and if these are used, a special oil level detection system must be assembled, which causes a large cost increase.

Further, since a dedicated thermosensor (for example, a thermistor) for detecting the oil temperature has been conventionally used, this also increases the cost.

Therefore, an object of the present invention is to provide a belt type continuously variable transmission capable of detecting the oil amount and the oil temperature of hydraulic oil at low cost.

[0006]

A belt type continuously variable transmission according to a first aspect of the present invention is connected to each other via a belt mounted between a fixed flange and a movable flange, and each belt pitch diameter is changed by a flange spacing operation. To change the gear ratio, a spring that applies tension to the belt by pressing the movable flange toward the fixed flange side, and move the movable flange of at least one of the speed change pulleys toward the fixed flange side for flange spacing operation. A hydraulic actuator to perform, an oil pump that pressurizes oil from an oil source to generate an operating oil pressure of the hydraulic actuator, a control valve that controls the operating oil pressure, a current detection resistor that detects the current of the control valve, and a control valve The gear ratio is controlled via the, and the oil amount decrease abnormality of the oil source is detected based on the oil temperature abnormality detected from the current value change of the current detection resistor. Characterized by comprising a controller.

The belt type continuously variable transmission according to the second aspect of the present invention determines the hydraulic pressure of the hydraulic oil from the operating state of the control valve, and detects an abnormality in the oil amount and an abnormal oil cooling system from the abnormal oil temperature and hydraulic pressure of the hydraulic oil. The belt type continuously variable transmission according to claim 1, which is detected by a controller.

The belt type continuously variable transmission according to the third aspect of the invention is provided with a required device for notifying an oil amount reduction abnormality and a required device for notifying an oil cooling system abnormality, and the controller operates these required devices in accordance with the occurrence of each abnormality. The belt type continuously variable transmission according to claim 2.

[0009]

[Function] By incorporating the current detection resistance in the control valve for controlling the hydraulic pressure supplied to the hydraulic actuator, and utilizing the fact that the oil temperature rises and the resistance value of the control valve increases when the oil quantity decreases, Abnormality of oil decrease is detected from abnormal temperature.

According to the second aspect of the present invention, the hydraulic pressure of the hydraulic oil is detected from the operating state of the control valve, and the abnormality of the oil amount and the abnormality of the oil cooling system are detected from the abnormal oil temperature and hydraulic pressure of the hydraulic oil.

In the third aspect of the present invention, these oil amount reduction abnormality and oil cooling system abnormality are displayed by different required devices, respectively, to enable quick inspection and repair.

In each of the inventions, the abnormality of the oil temperature and the oil amount can be detected by a simple structure in which the control valve cooled by the passing oil is provided with the current detecting resistor, and the cost is extremely low as compared with the conventional example. Can be implemented in.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the third invention will be described with reference to FIGS. The left and right directions are the left and right directions in FIG.
Members and the like not given reference numerals are not shown.

The belt type continuously variable transmission 1 of the embodiment is used to drive a vehicle accessory.

As shown in FIG. 1, the mechanical portion of the belt type continuously variable transmission 1 is provided with an increasing / decreasing gear set 3, a drive side speed change pulley 5, a driven side speed change pulley 7, and the like. These are housed in a casing 9 in which lubricating oil is sealed.

The speed increasing gear set 3 is composed of large and small gears 11 and 13 meshing with each other. The large gear 11 is supported by a shaft 15 whose both ends are supported by a casing 9 via bearings 17 and 17, and 13 is fixed to the drive shaft 19,
The drive shaft 19 is supported by the casing 9 via bearings 21 and 23. The large gear 11 meshes with the output gear on the crankshaft side of the engine, and the driving force of the engine is increased by the speed increasing gear set 3 to rotate the drive shaft 19. Between the small gear 13 and the casing 9, the speed increasing gear portion 3 is provided.
A seal 25 is arranged to prevent oil from leaking to the outside.

The speed change pulley 5 has a fixed flange 27 integral with the drive shaft 19 and a movable flange 29. The movable flange 29 is formed between a hub 31 spline-connected to the outer periphery of the drive shaft 19 and a torque cam. It is connected to the drive shaft 19 by 33 so as to be movable in the axial direction while rotating.

The speed change pulley 7 is provided with a fixed flange 37 integral with the driven shaft 35 and a movable flange 39, and the movable flange 39 is formed between a driven shaft 35 and a hub 41 spline-connected to the outer periphery of the driven shaft 35. It is connected to the driven shaft 35 by 43 so as to be movable in the axial direction while rotating. The driven shaft 35 is supported by the casing 9 via bearings 45 and 47, and a pulley 49 is fixed to the left end portion penetrating the casing 9. The pulley 49 is connected to the auxiliary pulleys on the oil pump side and the alternator side by belts mounted in the grooves 51 and 53. A seal 55 is arranged between the pulley 49 and the casing 9 to prevent oil from leaking to the outside.

The speed change pulleys 5 and 7 are connected via a belt 61 mounted in V grooves 57 and 59 formed between the flanges. Movable flange 39 of speed change pulley 7 and hub 4
A disc spring 63 (spring) is arranged between the disc spring 1 and the pressure roller 1 to press the movable flange 39 toward the fixed flange 37 to apply tension to the belt 61.

Each of the torque cams 33 and 43 has a movable flange 29 and a movable flange 29 when the belt tension suddenly increases due to torque fluctuation.
39 is pressed toward the fixing flanges 27 and 37 to increase the frictional force and to prevent the level 61 from slipping.

The hub 31 of the speed change pulley 5 is integrally formed with a partition 67 having a seal ring 65 arranged between the hub 31 and the movable flange 29. A pressure chamber 69 (hydraulic actuator) is formed between the partition 67 and the movable flange 29. The pressure chamber 69 is supplied with oil pressure from an oil pump 79 through an oil passage 71 formed through the casing 9 and the drive shaft 19, an oil plug 73, an oil line 75, and a control valve 77, and the movable flange 29 is fixed to a fixed flange. Two
Press to the 7 side. The oil pump 79 introduces oil from an oil reservoir 81 (oil source) at the bottom of the casing 9 through a strainer (not shown) and pressurizes it to generate this working hydraulic pressure.

When no hydraulic pressure is supplied to the pressure chamber 69, the flange spacing of the transmission pulley 7 is minimized (belt pitch diameter R ₂ by the biasing force of the disc spring 63 as in the lower half of FIG. 1).
1), the transmission pulley 5 receives the belt tension as in the upper half portion in FIG. 1 to maximize the flange spacing (belt pitch R ₁ minimum) and minimize the speed increasing ratio.

When hydraulic pressure is supplied to the pressure chamber 69, in the speed change pulley 5, the movable flange 29 is pressed as in the lower half of FIG. 1 to narrow the flange interval and increase the belt pitch diameter R _1. Then, as shown in the upper half of FIG. 1, the belt tension widens the belt spacing to reduce the belt pitch diameter R ₂ and increase the speed increasing ratio. When the hydraulic pressure is further applied to maximize the belt pitch diameter R ₁ and minimize R ₂ , the speed increasing ratio is maximized.

The driving force of the engine input through the speed increasing gear set 3 is changed to a required rotation speed between the speed change pulleys 5 and 7 to rotationally drive the oil pump and the alternator.

FIG. 2 shows a control system of the belt type continuously variable transmission 1 (CVT).

The controller 83 monitors the gear ratio by an input rotation sensor 85 for detecting the rotation speed of the speed change pulley 5 and an output rotation sensor 87 for detecting the rotation speed of the speed change pulley 7, while maintaining a predetermined rotation speed of the oil pump and the alternator. The duty ratio control of the control valve 77 is performed in accordance with the rotation command signal 89 for commanding the number, and the gear ratio is adjusted so that each accessory rotates at a predetermined rotation speed even if the engine rotation speed changes, for example. This gear ratio control is performed according to the main routine program.

Further, the controller 83, when an abnormality occurs in the oil cooling system and the oil amount in the oil sump 81 as described below, causes a cooling system abnormality lamp 91 provided in the driver's seat.
The (required device) and the oil amount decrease abnormality lamp 93 (required device) are turned on, an alarm signal 95 is generated, and the belt type continuously variable transmission 1 and the belt-type electromagnetic clutch disposed between the respective auxiliary devices. Disconnect the continuously variable transmission 1 from the load.

FIG. 3 shows the internal structure of the controller 83 and the connection with the control valve 77.

CPU 99 built in the controller 83
The drive element 101 converts the electric power of the power source 103 into a high-frequency pulse to control the duty ratio of the control valve 77 to adjust the hydraulic pressure of the pressure chamber 69, and the voltage of the power source 103 is input and stored.

The control valve 77 is cooled by the oil passing through the inside thereof, and a resistor 105 for current detection is incorporated near the oil passage. The change in the current value flowing through the resistor 105 is amplified by the amplifier 107 and the CPU
Sent to 99.

Next, an oil system abnormality diagnosis program executed by the controller 83 will be described with reference to the flowchart of FIG. This program is a subroutine that interrupts the main routine program described above at regular time intervals. The symbols in FIG. 4 have the following meanings.

V: voltage applied to the control valve 77 (V) I: current detection resistor 1 incorporated in the circuit of the control valve 77
Current flowing through 05 (A) R ₁ ... Circuit resistance (Ω) of the control valve 77 including the current detection resistor 105 T ₁ ... Temperature of the control valve 77 (° C) R ... Control valve including the current detection resistor 105 It is a value obtained by measuring the circuit resistance (Ω) of 77 at the time of factory shipment under a constant temperature, and is stored in the CPU 99.

T is the temperature of the control valve 77 when the above R is measured at the time of factory shipment and is stored in the CPU 99.

T _max ... Belt type continuously variable transmission 1 (CVT)
Is an allowable upper limit temperature of, and is stored in the CPU 99.

When the abnormality diagnosis program is started, V and I are measured in step S1.

In step S2, R ₁ is calculated from V / I.

In step S3, T 1 is calculated from R ₁ and the following equation.

T ₁ = R ₁ (234.5 + T) /R-234.5 In step S 4, it is determined whether T ₁ is lower than T _max . If it is low (YES), it is determined that the oil system is normal, and this abnormality diagnosis program is terminated. If high (N
O) Go to step S5.

In step S5, it is determined that the oil temperature is abnormally high, and the process proceeds to step S6.

In step S6, it is determined based on the operating state of the control valve 77 whether or not the operating oil pressure has risen to the extent that gear shifting operation can be performed. If the oil pressure is increased (YES), the process proceeds to step S7, and if the oil pressure is insufficient (NO), the process proceeds to step S8.

In step S7, the oil temperature is abnormally high as in the determination results of steps S5 and S6, but it is determined that an abnormality has occurred in the oil cooling system because the oil pressure is sufficient, and the process proceeds to step S9. move on.

In step S8, as in the determination results of steps S5 and S6, it is determined that the oil amount decrease abnormality has occurred because the oil temperature is abnormally high and the oil pressure is abnormally low, and the process proceeds to step S10.

In step S9, the cooling system abnormality lamp 91
Turn on to prompt inspection and repair.

In step S10, the oil amount decrease abnormality lamp 93 is turned on to prompt inspection and repair.

In step S11, the alarm signal 95 is output and the diagnostic program is terminated. As described above, according to the alarm signal 95, the belt type continuously variable transmission 1 is separated from the load and is prepared for inspection and repair.

Thus, the belt type continuously variable transmission 1 is constructed, and the control valve 77 has the current detecting resistor 1 as described above.
It is possible to detect an abnormal decrease in the oil amount based on the oil temperature abnormality detected by a simple configuration in which 05 is incorporated. Therefore, the implementation cost is extremely low as compared with the conventional example using an expensive oil level gauge. Further, according to the third invention as in this embodiment, the abnormality is displayed by the contents-specific lamps 91 and 93, so that the inspection and repair becomes easier. Further, the alternate long and short dash line in FIG. 3 indicates that the current detecting resistor 105 of the control valve 77 is incorporated in the controller 84, and the working oil that passes through the control valve 77 is partially introduced to the controller 83 side to change the temperature. To detect the current, and has the same effect as the above-described embodiment.

The required device is not limited to the warning lamp, but may be an alarm buzzer, for example.

[0048]

According to the belt type continuously variable transmission of the present invention, the abnormality of the oil temperature and the oil amount can be detected inexpensively with a simple structure by detecting the current of the control valve for controlling the operating oil pressure.

In the second invention, the details of the failure of the oil system are specified by the oil temperature and the hydraulic pressure of the hydraulic oil, and in the third invention, the specified failures are displayed according to the contents to facilitate inspection and repair.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a third invention.

FIG. 2 is a block diagram showing a control unit of the embodiment of FIG.

3 is a block diagram showing an internal configuration of a controller used in the embodiment of FIG. 1 and a connection with a control valve.

4 is a flowchart showing an abnormality diagnosis program in the embodiment of FIG.

FIG. 5 is a cross-sectional view of a conventional example.

FIG. 6 is a cross-sectional view of a first oil level gauge used in a conventional oil level detection system.

FIG. 7 is a sectional view of a second oil level gauge used in a conventional oil level detection system.

FIG. 8 is a sectional view of a third oil level gauge used in a conventional oil level detection system.

[Explanation of symbols]

 1 Belt Type Continuously Variable Transmission 5, 7 Variable Speed Pulley 27, 37 Fixed Flange 29, 39 Movable Flange 61 Belt 63 Disc Spring (Spring) 69 Pressure Chamber (Hydraulic Actuator) 77 Control Valve 79 Oil Pump 81 Oil Sump (Oil Source) 83, 84 Controller 91 Cooling system abnormality lamp (required device) 93 Oil amount decrease abnormality lamp (required device) 105 Current detection resistor

Claims (3)

[Claims] 1. A pair of speed change pulleys, which are connected to each other via a belt mounted between a fixed flange and a movable flange, and which change a belt pitch diameter by a flange spacing operation to change a gear ratio, and a movable flange. A spring that presses the flange side to give tension to the belt, a hydraulic actuator that moves the movable flange of at least one speed change pulley to the fixed flange side to perform flange spacing operation, and a hydraulic actuator that pressurizes oil from the oil source. The oil pump that generates the working oil pressure, the control valve that controls this working oil pressure, the current detection resistor that detects the current of the control valve, the gear ratio is controlled via the control valve, and the current of the current detection resistor A belt-type device, which is equipped with a controller for detecting an oil amount decrease abnormality of an oil source based on an oil temperature abnormality detected from a value change. Gearbox. 2. The belt according to claim 1, wherein the hydraulic pressure of the hydraulic oil is determined from the operating state of the control valve, and the controller detects an oil amount decrease abnormality and an oil cooling system abnormality based on the hydraulic oil temperature and hydraulic pressure abnormality. Type continuously variable transmission. 3. The belt type stepless apparatus according to claim 2, wherein a required device for notifying an oil amount reduction abnormality and a required device for notifying an oil cooling system abnormality are provided, and the controller activates these required devices upon occurrence of each abnormality. transmission.