JPH06280951A - Belt type continuously variable transmission - Google Patents

Abstract

PURPOSE:To prevent breakage of a driven unit of a transmission by furnishing a controller which can make self-checking of failure in the shifting function on the basis of the difference between measurement and the command value of gear ratio. CONSTITUTION:In a belt type continuously variable transmission, the control oil pressure is not supplied to an oil pressure chamber 51 but released to drain when a control valve 17 duty controlled by a controller 19 is opened fully, and the pitch diameter of a shift pulley 11 is maximized by the energization force of an initially coned disc spring 83, and the gear ratio of shift pulleys 9, 11 is maximized. When the degree of opening of the control valve 17 is lessened, on the other hand, the control oil pressure of the oil pressure chamber 51 rises, and a movable flange 25 moves toward a stationary flange 23, and the gear ratio is lessened. Therein the controller 19 judges after the start of the engine whether the gear ratio is smaller than the value obtained by adding an allowable value (for example, 0.1) to the command value (for example, 2.0) for the max. deceleration, and if the result is no, judgement is passed that the belt 3 is in failure in elongation.

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 Japanese Unexamined Patent Publication No. 64-46056 discloses an engine accessory drive device 201 as shown in FIG.
This is a belt type continuously variable transmission for transmitting the driving force of the engine to the auxiliary machine by the transmission pulleys 213, 215 connected via the belt 211 mounted between the movable flanges 203, 205 and the fixed flanges 207, 209. Machine 21
7, a hydraulic actuator 219 for moving the movable flange 205 to change the gear ratio, and a control valve 22 for giving the hydraulic pressure of the oil pump 221 to the hydraulic actuator 219.
3 and a controller 2 for adjusting the opening degree of the control valve 223 according to the fluctuation of the engine speed and the required output of the auxiliary machine.
25 and so on.

[0003]

However, the belt 211
Expansion and disconnection, hydraulic system abnormality from oil pump 221 to hydraulic actuator 219, movable flanges 203, 2
If 05 is stuck, the desired gear ratio cannot be obtained,
In the high speed rotation range of the engine, the auxiliary machine may be damaged due to excessive rotation, but the above-mentioned conventional example does not have a function of detecting such an abnormality.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a belt type continuously variable transmission which detects an abnormality in a gear shift function and prevents damage to a driven machine.

[0005]

A belt type continuously variable transmission according to the present invention is connected via a belt mounted in a V groove between a fixed flange and a movable flange, and changes a speed increasing ratio in accordance with a change in flange spacing. A pair of speed change pulleys, a spring that presses the movable flange toward the fixed flange to apply tension to the belt, a speed change operation unit that moves and operates the movable flange against the belt tension, and the speed change operation unit described above. A controller for controlling the gear ratio and self-checking for an abnormality in the gear changing function from the difference between the command value and the actually measured value of the gear ratio are provided.

[0006]

[Function] The controller self-checks for an abnormality of the belt, the movable flange, the hydraulic system, or the like from the difference between the commanded gear ratio and the actual gear ratio. Avoid damage to the driven machine by taking measures such as stopping the operation.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described with reference to FIGS. FIG. 1 shows a belt type continuously variable transmission 1 according to an embodiment, and FIG.
5 to FIG. 5 are flowcharts for self-checking for an abnormality in the gear shifting function. Further, the left and right directions are the left and right directions in FIG. 1, and members and the like without reference numerals are not shown.

As shown in FIG. 1, the belt-type continuously variable transmission 1 is connected through a belt 3 to the transmission pulleys 9 and 11 housed in a casing 7, a speed increasing gear set 13, and an oil pump 1.
5, a control valve 17, and a controller 19.

The input side speed change pulley 9 is provided with a fixed flange 23 integral with the drive shaft 21 and a movable flange 25. A hub 27 is spline-connected to the outer circumference of the drive shaft 21, and the movable flange 25 is connected by a torque cam 29 formed between the drive flange 21 and the hub 27 so as to be movable in the axial direction while relatively rotating with respect to the drive shaft 21. There is. The belt 3 is attached to the V groove 31 formed between the flanges 23 and 25. The drive shaft 21 is supported on the casing 7 by bearings 33 and 35.

The speed increasing gear set 13 is composed of large and small gears 37 and 39 meshing with each other, and the large gear 37 is supported by a shaft 41 whose both ends are supported by the casing 7 through bearings 43 and 43. 39 is fixed to the drive shaft 21. A seal 45 is arranged between the pinion 39 and the casing 7. The speed increasing gear set 13 speeds up the driving force from the engine and transmits it to the driving shaft 21.

The hub 27 has an O between the movable flange 25 and the hub 27.
A partition 49 in which the ring 47 is arranged is integrally formed, and a hydraulic chamber 51 is formed between the partition 49 and the movable flange 25. Control oil pressure from the oil pump 15 is supplied to the oil pressure chamber 51 via the oil passage 53 formed through the casing 7 and the drive shaft 21, the oil plug 55, and the control valve 17, and the movable flange 25 is fixed. It is moved to the flange 23 side. These oil pumps 15
The control valve 17, the hydraulic chamber 51 and the like constitute a gear shift operation means 57.

The output-side speed change pulley 11 includes a fixed flange 61 integral with the driven shaft 59 and a movable flange 63. A hub 65 is spline-connected to the outer periphery of the driven shaft 59, and the movable flange 63 is connected by a torque cam 67 formed between the driven flange 59 and the driven shaft 59 so as to be movable in the axial direction while relatively rotating with respect to the driven shaft 59. There is. The belt 3 is attached to the V groove 69 formed between the flanges 61 and 63.

The driven shaft 59 is supported by the casing 7 via bearings 71 and 73, and a pulley 75 is fixed to the left end portion penetrating the casing 7. This pulley 75
Is connected to an accessory side pulley such as an air compressor for a freezer via a belt mounted in each groove 77, 79. A seal 81 is arranged between the pulley 75 and the casing 7.

A disc spring 83 (spring) is arranged between the movable flange 63 of the speed change pulley 11 and the hub 65, presses the movable flange 63 toward the fixed flange 61, and applies tension to the belt 3.

An oil pump 85 that rotates in conjunction with the drive shaft 21 is arranged on the left side of the speed change pulley 9, and oil is sent from an oil line 89 through an oil passage 87 formed in the casing 7 and the driven shaft 59. Lubricate the sliding portion of the movable flange 63, the torque cam 67, and the like. In addition, the torque cams 29 and 67 move the movable flanges 25 and 63 to the fixed flanges 23 and 61 when the belt tension rapidly increases due to torque transmission.
It is pressed to the side to prevent the belt 3 from slipping.

The controller 19 adjusts the opening of the control valve 17 by controlling the duty ratio. When the control valve 17 is fully opened, the control hydraulic pressure escapes to the drain and is not supplied to the hydraulic chamber 51. In this state, the pulley pitch diameter R ₂ of the speed change pulley 11 is maximized by the biasing force of the disc spring 83, and the pulley pitch diameter R ₁ of the speed change pulley 9 is minimized due to the belt tension. Is the maximum (maximum deceleration state). Further, when the opening degree of the control valve 17 is reduced, the control hydraulic pressure in the hydraulic chamber 51 rises, the movable flange 25 is moved to the fixed flange 23 side against the belt tension, and the pulley pitch diameter R ₁ increases and the belt tension increases. As a result, the movable flange 63 retracts from the fixed flange 61 against the disc spring 83, the pulley pitch diameter R decreases, the gear ratio decreases, and the speed increases.

The opening degree of the control valve 17 is adjusted by the controller 19, and the gear ratio between the speed change pulleys 9 and 11 is controlled between the graphs 91 and 93 in FIG. Graph 91
Indicates the maximum speed increase state with the gear ratio H = 0.55, and the graph 9
The gear ratio 3 is the maximum deceleration state with the gear ratio H = 2.0. Further, the graph 95 shows a constant speed condition with the gear ratio H = 1.0, the vertical line graph 97 shows the rotational speed (Emax) of the speed change pulley 9 corresponding to the upper limit of the engine rotational speed, and the horizontal line graph 99. Is an allowable limit rotational speed (Cmax) of the air compressor.

Therefore, the range surrounded by the graphs 91, 93, and 97 is the speed change range of the speed change pulleys 9 and 11, and the lower side of the graph 99 (indicated by the horizontal line) in this speed change range has a normal speed change function. In this case, the shift range of the air compressor is shown, and the upper side of the graph 99 (displayed with diagonal lines) is the over-rotation range of the air compressor.

Next, each step such as control of the belt type continuously variable transmission 1 and self-check of the speed change function will be described with reference to the flowcharts of FIGS. 3, 4 and 5.

FIG. 3 shows an initialization routine executed by the controller 19 every time the engine of the vehicle is started.

In step S1, the engine speed is read.

In step S2, it is determined whether or not the read engine speed reaches 400 rpm (idling speed), and if 400 rpm or less, the process proceeds to step S3.
If it exceeds 400 rpm, the process proceeds to step S4.

In step S3, the engine load is reduced so that the engine speed rises quickly to 400 rpm. Therefore, the controller 19 fully opens the control valve 17 (Duty = 100% output) to release the control hydraulic pressure in the hydraulic chamber 51, and maximizes the gear ratio (H = 2.0, maximum deceleration). Then, the process returns to step S1.

In step S4, the gear shift function is diagnosed as described later by the self-check subroutine shown in FIG. 5, and if normal, the main routine of FIG. 4 is started.

Next, each step of the main routine will be described with reference to FIG.

In step S5, the measured values of the rotation speed of the transmission pulley 9 (input rotation speed Dr) and the rotation speed of the transmission pulley 11 (output rotation speed Dn) are read. The Dr rotation speed is obtained by multiplying the engine rotation speed by a constant K, and the Dn rotation speed is directly measured by a rotation speed sensor.

In step S6, it is determined whether the Dn rotation speed is lower than the allowable limit rotation speed of the air compressor, which is 4500 rpm (corresponding to the graph 99 in FIG. 2), and an overrun check is performed. If the Dn rotation speed is 4500 rpm or more, the vehicle is in an overrun state and the process proceeds to step S7.
If it is less than 500 rpm, the process proceeds to step S8.

In step S7, the gear ratio H is set to 2.0 in order to prevent damage to the air compressor, and the process returns to the beginning of the main routine. This is because if the cause of the overrun is the fixation (hanging) of the movable flanges 25, 63, the normal state may be restored by repeating the moving operation.

In step S8, the gear ratio H = Dr / Dn
Is calculated.

In step S9, it is determined whether the calculated gear ratio is within a predetermined range (0.55 to 2.0). If the gear ratio is not within the predetermined range, the ratio (gear ratio) is abnormal, and the process proceeds to the self-check subroutine of FIG.

In step S10, the gear ratio command value S is read from the map in the controller 19 in order to keep the internal temperature of the freezer constant. This S is commanded so that Dn is within the range of graphs 91, 93 and 97 in FIG. 2 and is between 0.55 and 2.0.

In step S11, the duty ratio corresponding to the command value S is calculated, the opening degree of the control valve 17 is adjusted by the controller 19, and the process returns to the start.

Next, each step of the self-check subroutine will be described with reference to FIG.

After the start, the ratio check on the deceleration side is first performed.

In step S12, the maximum deceleration (H = 2.
0) to start the timer. The timer is set to 2 seconds in order to stabilize the state after shifting.

In step S13, it is determined whether the timer has passed 2 seconds. If it is less than 2 seconds, repeat step S13 again, and if it exceeds 2 seconds, step S13 is repeated.
Move to 14.

In step S14, the gear ratio H is 2.10.
By determining whether or not it is smaller, it is diagnosed whether or not the belt 3 has an unacceptable elongation. Since H becomes larger than 2.0 when the belt 3 extends, 2.10 is the command value 2.0 plus the allowable value 0.1. H
Is greater than 2.10, it is determined that the ratio is abnormal, and the process proceeds to step S15. If H is smaller than 2.10, it is determined that the elongation of the belt 3 is within the allowable range and step S16 is performed.
Move to.

In step S15, since the belt is not recovered, the alarm signal indicating that the belt has expanded is output to prompt the conversion of the belt.

Thereafter, the control and operation of the belt type continuously variable transmission 1 are stopped.

In step S16, the gear ratio H is 1.90.
Whether or not the movable flanges 25 and 63 are stuck on the deceleration side is diagnosed by determining whether or not they are larger. 1.90 is a value obtained by subtracting an allowable value 0.1 from the command value 2.0. If H is 1.90 or less, it is determined that the movable flange is fixed, and the process proceeds to step S17, where H is 1. If it is larger than 90, the process proceeds to step S20.

In steps S17 and S18, the possibility of overrun of the air compressor due to the fixed movable flange is checked.

In step S17, H = 2.0 is commanded.

In step S18, it is determined whether H is larger than 1.00. As shown in the graph 95 of FIG. 2, H is set to 1.0. If H is 1.0, the rotation speed of the air compressor is allowed in the graph 99 in the engine rotation speed fluctuation range (left side of the graph 97). This is because the limit speed is not exceeded. If H is 1.00 or less, the process proceeds to step S19. If H is greater than 1.00, overrun due to the movable flange sticking on the deceleration side does not occur, and therefore the process returns to the first step S12.

In step S19, the range where H is 1.00 or less is in the upper left of the graph 95, and the air compressor may enter the overrun range in the high engine speed range, so an alarm signal to that effect is output. To do.

Thereafter, the control and operation of the belt type continuously variable transmission 1 are stopped.

From step S20 onward, a ratio check on the speed increasing side is performed.

In step S20, the maximum speed increase (H = 0.5)
Command 5) to start the timer. The timer is set to 2 seconds in order to stabilize the condition after shifting is completed.

In step S21, it is determined whether or not the timer has passed 2 seconds. If it is 2 seconds or less, repeat step S21 again, and if it exceeds 2 seconds, step S2
Move to 2.

In step S22, the gear ratio H is 0.50.
By determining whether or not it is larger, it is diagnosed whether or not the belt 3 has an unacceptable elongation. 0.
Reference numeral 50 is a command value 0.55 minus an allowable value 0.05. If H is 0.50 or less, the ratio is abnormal and the process proceeds to step 15. If H is larger than 0.50, the belt 3 is stretched. Is determined to be within the allowable range and step S2
Move to 3.

In step S23, the gear ratio H is 0.60.
By determining whether or not it is smaller, it is diagnosed whether or not the movable flanges 25, 63 are stuck on the speed increasing side. 0.60 is a command value of 0.55 plus an allowable value of 0.05. If H is 0.60 or more, it is determined that the movable flange is fixed, and the process proceeds to step S17. If it is smaller than 60, the self-check sub-routine is ended, and as shown in FIG. 3, the initialization routine proceeds to the main routine.

If the belt 3 is cut or the control oil pressure is abnormal,
Each of the above steps S9, S14, S16, S22, S2
These failures are not left as they are because they are detected by 3 or the like.

Since the belt type continuously variable transmission 1 is provided with the above-described shift function check function, self-check of the shift function is performed, for example, immediately after the engine is started (initialization routine), or an abnormality occurs. At this time, the command can be temporarily suspended (main routine). Therefore, the abnormality is immediately detected, the driven machine is effectively protected, and the reduction of fuel consumption of the engine is prevented.

[0053]

In the belt type continuously variable transmission of the present invention, for example, when an abnormality in the gear shifting function occurs after the engine is started or during operation, failure diagnosis is performed by the self-check function, so that the driven machine fails and the engine fuel consumption decreases. Etc. are prevented in advance.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of an example.

FIG. 2 is a graph showing characteristics of this example.

FIG. 3 is a flow chart of an initialization routine in this embodiment.

FIG. 4 is a flow chart of a main routine in this embodiment.

FIG. 5 is a flowchart showing a self-check subroutine of this embodiment.

FIG. 6 is a configuration diagram of a conventional example.

[Explanation of symbols]

 1 Belt type continuously variable transmission 3 Belt 9, 11 Speed change pulley 19 Controller 23, 61 Fixed flange 25, 63 Movable flange 31, 69 V groove 57 Speed change operation means 83 Disc spring (spring)

Claims (1)

[Claims] 1. A pair of speed change pulleys, which are connected via a belt mounted in a V groove between a fixed flange and a movable flange and change a speed increasing ratio according to a change in flange spacing, and a movable flange that is pressed against the fixed flange side. A spring for applying tension to the belt, a gear shift operating means for moving the movable flange against the belt tension, the gear ratio is controlled via the gear shift operating means, and a command value and a measured value of the gear ratio are also provided. A belt-type continuously variable transmission characterized by comprising a controller for self-checking for an abnormality in the gear shifting function from the difference between