JP2992541B2 - Device for preventing erroneous operation of hydraulic-mechanical continuously variable transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention provides a variable displacement type hydraulic pump and a fixed displacement or variable displacement type hydraulic motor, and has an output split type or input type having a plurality of shift modes. The present invention relates to an electronic control device for preventing breakage of a transmission due to an erroneous shift operation in a split-type hydraulic-mechanical continuously variable transmission.

[Conventional technology]

For example, a variable displacement hydraulic pump driven from an input shaft as a continuously variable transmission that can perform a continuously variable transmission to obtain an arbitrary speed ratio and has a high transmission efficiency for speed change steering of a high-speed tracked vehicle, and Two sets of hydraulic pump motor units are provided, consisting of a hydraulic pump and a fixed displacement hydraulic motor connected in a closed circuit, one set for shifting and another set for steering; third and fourth planetary gears The sun gears of the device are connected to each other by a shaft and connected to the output shaft of the transmission hydraulic pump motor via a shaft and a gear; and the ring gears of the third and fourth planetary gear units are connected to the carrier of the first planetary gear unit through members. The carrier of the fourth planetary gear set is connected to the carrier of the second planetary gear set via a shaft; and four types of reduction and direct coupling mechanisms comprising the first and second planetary gear sets and four clutches are provided. It is provided on one shaft of the shaft; the coupling gear ratio from the input shaft to the first and second planetary gear units and the third and fourth planetary gear units is such that even if the clutch is sequentially switched and the mode changes, the output gear of the transmission unit is changed. A hydraulic-mechanical continuously variable transmission whose rotational speed is selected to be continuously connected is disclosed in
This is known from Japanese Patent No. 227045.

FIG. 4 shows a conventionally known hydraulic-mechanical continuously variable transmission (hereinafter referred to as the above) having a variable displacement hydraulic pump and a fixed displacement or variable displacement hydraulic motor and having a plurality of shift modes. , Abbreviated as a transmission) is a diagram showing an example (four-mode type) of a shift diagram. In the figure, the horizontal axis represents the speed ratio (the ratio between the output shaft rotation speed and the input shaft rotation speed of the transmission), and the vertical axis represents the hydraulic motor rotation speed (proportional to the hydraulic pump swash plate angle).

This continuously variable transmission has four shift ranges (modes 1 to 4).
have. The operation procedure for manually changing this from the speed ratio 0 to the maximum manually is as follows.

1) First, the number of revolutions of the hydraulic motor is set in advance to the maximum value on the plus (+) side, and the mode switch is turned on from the neutral position to the mode 1. Then, the clutch for mode 1 is engaged, and the state becomes point A, and the reduction ratio (speed of the output shaft) is zero.

2) Next, the point B is set when the rotational speed of the hydraulic motor is changed from the maximum value on the (+) side to neutral (0) by the knob or the like. This mode 1 is terminated, the speed ratio at this time is E _c.

3) Since the mode 1 is completed in the above 2), the mode switch is turned on to the mode 2. Then, only the mode is switched from 1 to 2 while keeping the hydraulic motor speed unchanged. The speed ratio also remains at EC corresponding to the point _C.

4) To increase the speed in mode 2, contrary to mode 1,
The number of rotations of the hydraulic motor is increased from the maximum value on the (-) side to neutral (0) and further to the maximum value on the (+) side. Thus, the speed ratio ED corresponding to the point _D is obtained.

5) In modes 3 and 4, the same repetitive operation as described above may be performed.

[Problems to be solved by the invention]

In the conventional transmission as described above, even if the operation is erroneously performed during the manual operation, the transmission only moves as instructed by a human. Therefore, for example, when decelerating from the maximum state (i.e., point D) of the hydraulic motor rotation speed (+) side in mode 3, the mode switch should be switched from mode 3 to mode 2, but the hand slips and switches to mode 1 When ever fall, it will be sharply reduced in the speed ratio from E _D to 0 corresponding to the point a. However, not to zero instantaneously what just before was speed ratio E _D up, the transmission inside the shaft, can lead to breakage subjected to any excessive force to the power transmission components such as gears are concerned.

[Means for solving the problem]

The present invention provides a hydraulic-mechanical continuously variable transmission that includes a variable displacement hydraulic pump and a fixed displacement or variable displacement hydraulic motor, and has a plurality of shift modes, in order to solve the conventional problem. In the manual switching between the rotation speed and the speed change mode, the mode is switched between continuous modes and only when the ratio between the output shaft rotation speed and the input shaft rotation speed is within a preset range. It is an object of the present invention to provide an apparatus for preventing an erroneous operation of a hydraulic-mechanical continuously variable transmission, which is provided with an electronic control device that allows the switching.

[Action]

In the present invention, when the hydraulic-mechanical continuously variable transmission is manually operated, the mode cannot be switched between the discontinuous modes, and only when the speed ratio between the output shaft and the input shaft is within the set range. Since the electronic control is performed so as to be switched, damage to the power transmission component due to an erroneous mode switching operation is prevented.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a shift diagram similarly, and FIG. 3 is a diagram showing a detailed configuration inside the electronic control device. First, in FIG. 1, (1) is a transmission body, (2) is an input shaft speed sensor for detecting a transmission input shaft speed, and (3) is an output shaft speed for detecting a transmission output shaft speed. A sensor, (4) indicates a hydraulic motor rotation speed control actuator, and (5) indicates a shift mode switching actuator. The input shaft speed sensor (2), the output shaft speed sensor (3), the hydraulic motor speed control actuator (4), and the shift mode switching actuator (5) are all electrically operated, and the electronic control device (6) ) Is electrically connected. The electronic control unit (6) includes a shift mode switching switch (7) that can manually operate the shift mode switching actuator (5) (selecting mode 1, mode 2, etc.), and a hydraulic motor speed control. Actuator (4)
Is provided with a hydraulic motor speed setting device (8) which can be operated by manual operation.

Next, in FIG. 3, a shift mode setting signal m output from a shift mode switching switch (7) set by a manual operation is input to a shift mode switching determining circuit (9). In the determination circuit (9), when the shift mode switching switch is fixed to a certain mode, that is, when the setting signal m does not change, the shift mode switching actuator operation signal M corresponding to the value of m.
Is output to the next-stage shift mode switching actuator (5). Further, an output shaft rotation speed calculation circuit (10) is incorporated in the electronic control device (6). The calculation circuit (10), the hydraulic motor speed signal h and the output from the input shaft rotational speed sensor (2) an input shaft which is output from the speed signal n _i and the hydraulic motor rotational speed setting unit (8) Shift mode setting signal m is input. Then, in the calculation circuit (10), the signal n _i, h, from the m, to calculate the signal n _o 'corresponding to the transmission output shaft speed rotation at the time capture the signal,
And outputs the n _o 'to the next stage of the output shaft rotational speed comparing circuit (11).

The output shaft speed comparison circuit (11) includes an actual output shaft speed signal output from the output shaft speed sensor (3).
n _o is inputted, it compares the magnitude of n _o and n _o 'the logical operation. The permissible speed ratio range delta (of FIG. 2 Δ12, Δ23, Δ34) which has been previously set before and after the mode switching point if contains both n _o and n _o 'the rotational speed value corresponding to, the mode switching allowable signal j and outputs it to the shift mode switching judgment circuit (9), needs to include any one of n _o and n _o 'in the delta, the shift mode switching determination circuit the current mode fixing signal l ( Output to 9).

When the value of the setting signal m input to the determination circuit (9) changes (when a shift mode switching operation is performed),
If the signal output from the comparison circuit (11) is the mode switching permission signal j, the shift mode switching actuator operation signal M corresponding to the value of m is output as described above. (For example, when the value of m requires switching from mode 1 to mode 2, the shift mode switching actuator (5) is operated to switch from mode 1 to mode 2.
Mode is switched). Conversely, if the signal output from the comparison circuit (11) is the current mode fixed signal l, the shift mode switching actuator operation signal M is not changed even if the setting signal m changes (for example, Even if the value of m requires switching from mode 1 to mode 3, the shift mode switching actuator (5) remains in the operating state of mode 1 before the request for switching.

As described above, even when a shift mode switching erroneous operation is performed, the erroneous operation prevention function of the electronic control device is activated, and damage to the power transmission components inside the transmission can be prevented.

The calculation in the calculation circuit (10) will be described in detail below. The speed of the output shaft of the continuously variable transmission is directly proportional to the engine speed that is input to the transmission itself (the speed of the output shaft also doubles when the engine speed doubles). Further, as described above, the speed (speed ratio) of the output shaft changes by two operations of switching the shift mode and changing the angle of the hydraulic pump swash plate (proportional to the number of rotations of the hydraulic motor). The input shaft rotation speed (n _i ) and the hydraulic motor rotation speed (h) are read, and if the mode (m) is known, the theoretical output shaft rotation speed can be obtained by calculation.

〔The invention's effect〕

According to the present invention, when a hydraulic-mechanical continuously variable transmission having a plurality of shift modes including a hydraulic pump / motor is manually operated, a power transmission component inside the transmission is caused by an erroneous shift mode switching operation. Damage can be prevented beforehand.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a shift diagram similarly, and FIG. 3 is a diagram showing a detailed configuration inside the electronic control device. FIG. 4 is a diagram showing an example of a shift diagram of a conventional hydraulic-mechanical transmission. (1) Transmission body, (2) Input shaft speed sensor, (3) Output shaft speed sensor, (4) Hydraulic motor speed control actuator, (5) Shift mode Switching actuator, (6) Electronic control device, (7) Shift mode switching switch, (8) Hydraulic motor speed setting device, (9) Shift mode switching determination circuit, (10) …… Output shaft speed calculation circuit, (11) …… Output shaft speed comparison circuit.

Continuation of the front page (56) References JP-A-60-227045 (JP, A) JP-A-61-75061 (JP, A) JP-B-60-53221 (JP, B2) JP-B-57-38832 (JP) , B2) (58) Fields surveyed (Int. Cl. ⁶ , DB name) F16H 47/02-47/04 F16H 39/00-63/48

Claims (1)

(57) [Claims] A variable displacement type hydraulic pump and a fixed displacement or variable displacement type hydraulic motor are provided, and the rotational speed and the shift mode of a hydraulic-mechanical continuously variable transmission having a plurality of shift modes are manually switched. An electronic control device for permitting mode switching only when switching between successive modes and when the ratio between the output shaft speed and the input shaft speed is within a preset range. A device for preventing erroneous operation of a hydraulic-mechanical continuously variable transmission.