JP2717671B2 - Mechanical hydraulic transmission and control method thereof - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a control method of a mechanical hydraulic power transmission device, and more particularly to a construction machine such as a wheel type power shovel and a rough terrain crane for high-speed continuous running. Power transmission system.

[Conventional technology]

2. Description of the Related Art Conventionally, the following method is often used for a transmission device such as a construction machine.

1.Mechanical power transmission system 2.Hydraulic power transmission system (HST) 3.Mechanical hydraulic power transmission system (HMT) Of these, the mechanical hydraulic power transmission system (HMT) As shown in FIG. 5, the output split type is improved among the power split type hydraulic transmissions (hydraulic-mechanical transmission) in which the power is transmitted and the remainder is transmitted by hydraulic pressure.

In the conventional transmission described above, the mechanical power transmission system is efficient, but the controllability of switching between forward and reverse operation is poor, and the hydraulic power transmission system (FIG. 6) uses the variable displacement pump 51 and the swash plate of the motor 52. By changing the tilt angle, it is easy to perform the switching control of the forward / reverse operation, which is easy.On the other hand, the speed can be changed by switching the gears 53 and 54, or the gears 55 and 56, and the clutches 57 and 58. However, there is a disadvantage that the tilt angle of the motor 52 is increased and the discharge flow rate is increased to increase the pressure loss, and the tilt angle of the motor 52 is reduced, so that the efficiency is reduced. Therefore, conventionally, mechanical power transmission is performed at high speed to avoid a decrease in efficiency, and at low speed, hydraulic power transmission is performed to facilitate switching control between forward and reverse operation. 5) are used in various fields. In FIG. 5, an input shaft 62 is connected to a power source 61, a gear 64 meshing with a hydraulic pump drive gear 63 is fixed to an intermediate portion of the input shaft 62, and a sun gear 65 of the planetary gear set A is fixed to an end. Is fixed. The hydraulic pump drive gear 63 drives a variable displacement pump 66 of a hydraulic transmission device B provided on one side of the input shaft 62. The variable displacement pump 66 is connected to the axis of the input shaft 62. The constant displacement motor 67 arranged in the direction is operated. An output shaft of the constant displacement motor 67 is provided with a hydraulic transmission passive gear 68. The planet gear between the driven gear 68 is a planetary gear device is connected to rotatably drive the internal gear 69 -1 A, the internal gear 69 -1 and the sun gear 65 by the gear 69 which meshes with it 70 are provided. This planetary gear 70
The shaft support frame 71 is connected to the output shaft 72 so as to transmit the revolving motion of the planetary gear 70, that is, the rotational motion of the shaft support frame 71 to a vehicle body 73 such as an appropriate construction machine. When the variable displacement pump 66 is in neutral, the hydraulic transmission B merely performs a braking action and the internal gear 69-1 is fixed, so that the planetary gear set A functions as a mechanical planetary reducer. The speed control of the output shaft 72 is performed by speed control means (not shown) such as a governor provided in the power source 61. When the variable displacement pump 66 operates, a part of the power is transmitted to the transmission elements 64 and 6.
3, 66, 67, 68, 69, 70 are transmitted in the order, and the other part is transmitted mechanically in the order of the transmission elements 62, 65, 70.

Japanese Patent Publication No. Sho 53-16750 shown in FIG. 7 is known as a conventional technique capable of switching between a hydraulic shift and a gear shift. FIG. 7 shows that the pump 153 is driven by the power of the engine 152 mounted on the body 151, the hydraulic motor 154 is driven by the pressure oil discharged from the pump 153, and the driving force of the hydraulic motor 154 is further increased. Gear 155 fixed to the hydraulic motor 154,
The power is transmitted to the wheels 158 via a mechanical transmission mechanism such as a gear 157 fixed to the drive shaft 156. In addition, the power of the engine 152 is transmitted from a transmission gear 161 which is slidably provided on an output shaft 160 of the engine via a gear 162 to a transmission shaft.
163, and further transmitted to the wheels 158, 158 via a drive shaft 156 integrated with the transmission shaft 163. Further, the transmission gear 161 is detachable from a clutch 166 provided on the pump shaft 165. Reference numeral 167 denotes a shift lever, and A to C show the positions of the levers during operation.

In this arrangement, when various shift speeds are used at a relatively low speed, the rotational power of the engine 152 is transmitted to the wheels 158, 158 via the hydraulic drive device by engaging the shift gear 161 and the clutch 166, that is, In addition, a variety of low speeds can be obtained, which is a characteristic of a hydraulic drive device and is stepless and powerful. Next, when traveling at a relatively high speed, such as when traveling on the road, the transmission gear 161 and the clutch 166 are disengaged, and the transmission gear 161 is moved to the gear 1.
62, the rotational power of the engine 152 is transmitted to the wheels 158, 158 via a drive shaft 156 integrated with the transmission shaft 163.
Conveyed to. This makes it possible to obtain a vehicle speed that makes use of the respective characteristics of the hydraulic drive device and the mechanical transmission mechanism, and releases the drive of the hydraulic drive device by a switching device provided in front of the hydraulic drive device, that is, on the engine side. If it is switched to drive the mechanical transmission side, the hydraulic pump will not be driven at all, so there is no drive loss, and therefore all the output of the engine is given to the mechanical transmission and it is powerful and high speed In addition, there is no need to worry about oil temperature rise because there is no unnecessary stirring and flow of pressure oil, and as a result,
The capacity of the pressure oil cooling device is also small.

In addition, for controlling the hydraulic drive device, for example,
JP-A-61-33328 is known. According to the publication, an engine rotation control device at the time of forward / reverse switching of a vehicle is described, and a continuously variable transmission including a variable displacement hydraulic pump driven by an engine and a hydraulic motor is illustrated. In addition, the forward and backward operation device is moved from forward to reverse, or
By switching from reverse to forward, the gear ratio data value output based on the operation amount of the travel operating device changes from the forward value to the reverse value, and the gear ratio of the continuously variable transmission is determined based on the gear ratio data value. To adjust. The speed ratio of the continuously variable transmission is adjusted by changing the discharge amount of the variable displacement hydraulic pump. A vehicle speed detector is mounted on the output shaft of the hydraulic motor,
The traveling speed is detected and the rotation direction of the hydraulic motor is determined. As a result, when the vehicle is switched from forward to reverse or from reverse to forward, the engine throttle is held in the idling state during deceleration. The engine brake at the time can be made more effective.

[Problems to be solved by the invention]

However, the conventional mechanical hydraulic power transmission system shown in FIG. 5 has the following disadvantages. That is,
Since the internal gear 69-1 is driven by the constant displacement motor 67, in order to change the output rotation speed from forward rotation to reverse rotation, a variable displacement pump 66 of a bidirectional discharge type is used as a hydraulic pump. and so it must rotate the internal gear 69 -1 considerably faster at the rotational speed with the output shaft 72,
The capacity ratio between the hydraulic pump and the hydraulic motor must be very large, and it is quite difficult to select such a hydraulic pump and a hydraulic motor. Further, since the gears use a planetary gear device, the structure is complicated and the cost is increased. Further, since the hydraulic pump, the hydraulic motor, and the planetary gear device constituting the hydraulic transmission device B are arranged side by side in the axial direction of the input shaft 62, there is a disadvantage that the entire device becomes large. Also, when the hydraulic circuit is switched and the discharge flow rate of the hydraulic pump is supplied to another hydraulic actuator of a working machine such as a construction machine for use, power is constantly transmitted to the output shaft 72. Even if the output shaft 72 is fixed with a brake or the like, the planetary gear 70 and the internal gear
Since the constant displacement motor 67 is rotated via the 69 -1 and the passive gear 68, there is a disadvantage in that power is lost due to loss of stirring.

Further, in Japanese Utility Model Publication No. 53-16750 shown in FIG. 7, the hydraulic pump does not receive the driving force by the clutch and therefore does not discharge the pressure oil. Therefore, as in the embodiment of FIG. 5, the hydraulic motor does not rotate because it does not receive the pressure oil from the hydraulic pump. However, according to this configuration, the hydraulic motor sequentially transmits the rotational power of the engine 152 to the transmission gear 161.
Gear 162, transmission shaft 163, drive shaft 15
6, gear 157 fixed to the drive shaft 156, and
It is received via a gear 155 fixed to the hydraulic motor 154. As a result, the hydraulic motor 154 functions as a pump, and the hydraulic motor 154 generates a drive loss as described above. For this reason, there is a problem that wasteful stirring and flow of the pressure oil occur, which causes an increase in the oil temperature.

In Japanese Patent Application Laid-Open No. 61-33328, only the speed of the vehicle is detected and the rotational speed of the engine and the hydraulic drive device are controlled in accordance with the vehicle speed.

The present invention focuses on the above problems, and relates to an improvement of a mechanical hydraulic power transmission system. Its purpose is 1. At high speed rotation, only mechanical power transmission is performed, and loss due to hydraulic pressure is substantially reduced. Becomes zero.

2. At low speeds, the change in output speed between forward and reverse rotation can be controlled smoothly and smoothly. Control of clutch engagement / disconnection at high speed or at low speed is automatically output from the control unit, and operation becomes easy.

3. Since a planetary gear device having a complicated mechanism is not used, the structure is extremely simple and the cost can be reduced.

4. The whole device can be made compact.

5. To provide a mechanical hydraulic transmission device that can use hydraulic energy without losing extra power when supplying a discharge flow rate of a hydraulic pump to another actuator by switching a hydraulic circuit. .

[Means for solving the problem]

In order to achieve the above object, the present invention provides a first aspect of a mechanical hydraulic transmission, wherein an input shaft connected to a prime mover having a rotation speed control means, an output shaft arranged in parallel with the input shaft, an input shaft and an output shaft. And a hydraulic transmission system comprising a mechanical transmission device comprising at least one clutch and one gear train, and a hydraulic pump and a hydraulic motor receiving discharge pressure from the hydraulic pump and transmitting power to the output shaft. A hydraulic transmission device directly connected to an input shaft or via a clutch, and a hydraulic transmission device connected directly to an output shaft or via a clutch. Hydraulic motor, an actuator that operates a working machine mounted on a vehicle traveling by a mechanical hydraulic transmission device by receiving hydraulic oil from a hydraulic pump, a hydraulic pump and a hydraulic motor Disposed between, characterized by comprising the hydraulic valve to supply pressure oil to the actuator of the working machine.

In the second aspect of the mechanical hydraulic transmission, at least one of an input shaft connected to a prime mover having a rotational speed control means, an output shaft arranged in parallel with the input shaft, and an input shaft and an output shaft is provided. Mechanical hydraulic transmission including a mechanical transmission including one clutch and one gear train, and a hydraulic transmission including a hydraulic pump and a hydraulic motor receiving discharge pressure from the hydraulic pump and transmitting power to the output shaft In the apparatus, a hydraulic pump of a hydraulic transmission device directly connected to an input shaft or through a clutch, a hydraulic motor of a hydraulic transmission device directly connected to an output shaft or through a clutch, and a mechanical hydraulic transmission device An actuator that operates a work machine mounted on a traveling vehicle by receiving hydraulic oil from a hydraulic pump and power from an input shaft is cut into one gear train of a mechanical transmission Or a transmitting clutch, a speed sensor for detecting a rotation speed of the output shaft, and a hydraulic pump and / or a hydraulic pump for outputting power to the output shaft by a hydraulic transmission when the rotation speed of the output shaft is lower than a predetermined value. Outputs a command to increase or decrease the discharge volume to the motor, outputs a command to disconnect the clutch to the mechanical transmission, and outputs a power to the mechanical transmission when the rotation speed of the output shaft is equal to or higher than a predetermined value. Control means for outputting a command to connect the clutch to the mechanical transmission for output to the output shaft and outputting a command to minimize the absorption torque to the hydraulic pump and the hydraulic motor; and It is characterized in that it comprises a hydraulic valve that is disposed between and supplies hydraulic oil to the actuator of the work machine.

In the third aspect of the mechanical hydraulic transmission, at least one of an input shaft connected to a prime mover having a rotation speed control means, an output shaft arranged in parallel with the input shaft, and an input shaft and an output shaft is provided. Mechanical hydraulic transmission including a mechanical transmission including one clutch and one gear train, and a hydraulic transmission including a hydraulic pump and a hydraulic motor receiving discharge pressure from the hydraulic pump and transmitting power to the output shaft A hydraulic pump of a hydraulic transmission coupled to the input shaft;
An intermediate shaft disposed between the input shaft and the output shaft for transmitting power from a mechanical transmission or a hydraulic motor to the output shaft; and an intermediate shaft disposed between the intermediate shaft and the output shaft. Mounted on a vehicle driven by a mechanical hydraulic power transmission, and a hydraulic motor coupled to the intermediate shaft and transmitting the power of the hydraulic power transmission via the clutch of the speed increase / reduction device. An actuator that operates the working machine that has received the pressure oil from the hydraulic pump,
Upon receiving signals from a speed sensor that detects the rotation speed of the output shaft and a signal from the speed sensor of the output shaft, when the rotation speed of the output shaft is equal to or less than a predetermined value, power is transmitted to the output shaft via a hydraulic transmission and a speed increasing and reducing device. In order to output, a command for engaging the clutch of the acceleration / deceleration device disposed between the intermediate shaft and the output shaft, and a command for increasing / decreasing the discharge volume to the hydraulic pump and the hydraulic motor are output. Output a command to disengage the clutch of the clutch of the clutch and the clutch of the acceleration / deceleration device, and output the power to the output shaft via the mechanical transmission device and the acceleration / deceleration device when the rotation speed of the output shaft is a predetermined value or more. Control means for reducing the discharge volume of the hydraulic pump and the hydraulic motor, and outputting a command for joining to the clutch of the mechanical transmission and the clutch of the speed increasing / decreasing device; It is arranged between the pressure motor, characterized by comprising the hydraulic valve to supply pressure oil to the actuator of the working machine.

According to a first invention, a second invention, and a fourth invention mainly of a mechanical hydraulic transmission, a hydraulic valve for a working machine that supplies pressurized oil to an actuator of the working machine, and a hydraulic motor for the hydraulic transmission Is characterized by being connected in parallel to the hydraulic pump.

According to the first, second, third, and fourth inventions of the mechanical hydraulic transmission, the output shaft rotates when the hydraulic valve supplies pressure oil to the actuator of the work machine. It is characterized in that the speed is equal to or less than a predetermined value or is zero.

According to a sixth aspect of the present invention, there is provided a mechanical hydraulic transmission device which receives a power of a prime mover having a rotational speed control means and transmits the power to an output shaft by a mechanical means, and a power source of a prime mover having a rotational speed control type. And a hydraulic motor having a hydraulic transmission system comprising a hydraulic motor for transmitting power to the output shaft upon receiving the discharge pressure oil from the received hydraulic pump. In a method of controlling a mechanical hydraulic transmission device that outputs to an output shaft by either a hydraulic transmission device or a mechanical transmission device,
When the rotation speed of the output shaft is equal to or less than a predetermined value, a working machine mounted on a vehicle traveling by the mechanical hydraulic transmission is operated by hydraulic oil from a hydraulic pump of the hydraulic transmission.

[Action]

According to the above configuration, in the case of the mechanical hydraulic transmission according to the present invention, when the hydraulic valve is provided between the pump and the motor, the forward / reverse switching is performed, and when the port is set to the neutral port, power is not transmitted to the output shaft and the pump discharges. The flow rate can be used for other hydraulic actuators and the like. Further, when a plurality of hydraulic valves are provided between the pump and the motor, one hydraulic valve can switch between forward and backward, and the other hydraulic valve can use the discharge flow rate of the pump for another hydraulic actuator or the like. . Further, since the pump and the motor are provided side by side with the mechanical transmission, the size of the device can be reduced.

Further, a clutch pressure control valve which is controlled by a controller at the time of power transmission of the mechanical hydraulic transmission device is provided, and the clutch of the mechanical transmission device is joined when the rotation speed of the output shaft is greater than a predetermined value. Disengage the clutch and transmit the power to the output shaft using a mechanical transmission with good transmission efficiency.When the rotation speed of the output shaft is less than a predetermined value, disconnect the clutch of the mechanical transmission and disconnect the clutch of the hydraulic transmission. Join and transmit power to output shaft. The control of the engagement and disengagement of the clutch is automatically output from the control unit, so that there is no need for the operator to perform the control. Therefore, the transmission efficiency is good at high speed, so that the power loss can be reduced, and at low speed, the output rotation speed between forward rotation and reverse rotation can be smoothly controlled.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. First
FIG. 1 is an overall configuration diagram of a mechanical hydraulic transmission showing a first embodiment of the present invention. The power source 1 having speed control means, a hydraulic transmission 10, a control device 20, and a mechanical transmission 30 are shown.
It is composed of The hydraulic transmission 10 includes a variable displacement hydraulic pump 11 (hereinafter, referred to as a pump 11) connected to be driven by the power source 1 via the input shaft 2, and a pump.
A variable displacement hydraulic motor 13 (hereinafter referred to as a motor 12) connected to a pipe 11 by a pipe 12 and an output shaft 14
Are driven to drive. Pump 11 and motor 13
Are provided with discharge volume control valves 15 and 16, and change the discharge capacity and outflow direction of the pump 11 and the discharge capacity of the motor 13 according to a command from the control unit 21. A speed sensor 25 is provided on the input shaft 2, and a speed sensor 25 is provided on the output shaft 14, and the number of revolutions is fed back to the control unit 21.
The mechanical transmission 30 includes a clutch 31 fixed to the input shaft 2.
A gear 32 rotatably inserted into the input shaft 2 and a gear 32
And a gear 33 fixed to the output shaft 14
The hydraulic pressure of the pump 23 is received via a clutch pressure control valve 24 controlled by the control unit 21, the clutch 31 is joined, and the output shaft 14 is rotated. A control unit 21 composed of a controller and the like is provided with switching means 26 such as a switching lever for switching between forward and backward movement of a construction machine and the like, and speed control means 28 such as an accelerator petal for controlling a vehicle speed. I have.

Next, the operation of the above configuration will be described. motor
When the rotation speeds of the output shaft 13 and the output shaft 14 are smaller than a predetermined value, the control unit 21 sends a signal to the clutch pressure control valve 24 to disconnect the clutch 31 of the mechanical transmission 30 fixed to the input shaft 2, and Power output shaft by transmission 10
14 to drive a starting wheel 100 of a vehicle body such as a construction machine (not shown).

At this time, a signal is sent from the control unit 21 to the discharge volume control valve 15 of the pump 11 and the discharge volume control valve 16 of the motor 13 by a signal from the speed control means 28 such as an accelerator petal, and the discharge capacities of the pump 11 and the motor 13 are output. , The rotation speed of the motor 13 or the output shaft 14 can be arbitrarily set without controlling the rotation speed of the power source 1. In addition, a pump from the control unit 21 is supplied by a signal from a switching means 26 such as a switching lever for switching between forward and backward movement of a construction machine.
A signal is output to the output shaft 11 and the discharge direction of the pump 11 is reversed by setting the discharge capacity of the pump 11 to a negative region, whereby the rotation direction of the output shaft 14 can be reversed.
Therefore, in a range where the output rotation speed is smaller than the predetermined value, the output rotation speed between the normal rotation and the reverse rotation can be smoothly controlled.

Next, when the rotation speed of the motor 13 and the output shaft 14 is in a range greater than a predetermined value and the rotation direction is controlled to be positive or forward, a signal is transmitted from the control unit 21 to the clutch pressure control valve 24. The clutch 31 of the mechanical transmission 30 fixed to the output output shaft 2 is connected, and power is transmitted to the output shaft 14 via gears 32 and 33. At this time, the discharge volume control valve 15 of the pump 11 and the discharge volume control valve 16 of the motor 13 are operated in accordance with a command from the control unit 21, and the discharge capacities of the pump 11 and the motor 13 are set to zero. As a result, the power absorbed by the motor 13 is minimized, and the power of the power source 1 is transmitted to the output shaft 14 only through the mechanical transmission 30 having good transmission efficiency. At this time, the speed control is performed by the control unit 21 based on a signal from the speed control means 27 such as an accelerator petal.
Is performed by speed control means (not shown).

FIG. 2 shows a second embodiment of the present invention. In this figure, the same parts as those of the first embodiment are denoted by the same reference numerals, and the description is omitted. The pump shaft 111 of the pump 11 connected to the hydraulic transmission 110 so as to be driven from the power source 1 via the input shaft 2.
Is provided with a pump clutch 112. The power from the motor 13 is transmitted to the output shaft 14 via a motor clutch 114 provided on the motor shaft 113. The pump clutch 112 and the motor clutch 114 receive and join the hydraulic pressure of the pump 23 via a clutch pressure controller valve 121 controlled by the control unit 21.

In the above configuration, when the rotation speeds of the motor 13 and the output shaft 14 are smaller than a predetermined value, the control unit 21 outputs a signal to the clutch pressure control valve 24, and the clutch 31 of the mechanical transmission 30 fixed to the input shaft 2 And a signal is sent from the control unit 21 to the clutch pressure control valve 121, the pump clutch 112 and the motor clutch 114 are joined, and the power is transmitted to the output shaft 114 by the hydraulic transmission device 110. Starting wheel of vehicle body 100
Is to be driven.

Next, when the rotation speeds of the pump 11 and the output shaft 14 are in a range greater than a predetermined value, and the rotation direction is controlled to be positive or positive, the control unit 21 sends a signal to the clutch pressure control valve 24. The clutch 31 of the mechanical transmission 30 fixed to the input shaft 2 is joined, and a signal is output to the clutch pressure control valve 121 to disconnect the pump clutch 112 and the motor clutch 114 to transmit the power by mechanical transmission. The information is transmitted to the output shaft 14 by the device 30. Therefore, the pump 11 and the motor 12 do not rotate, so that the power absorbed by the hydraulic transmission 110 can be reduced to zero, and the power of the power source 1 can be reduced by the mechanical transmission 30 having good transmission efficiency.
Only transmitted to the output shaft 14 via. In this example, the pump clutch 112 and the motor clutch 114 are provided in the hydraulic transmission 110, but may be provided in the mechanical transmission 30.

FIG. 3 shows a third embodiment of the present invention. In this figure, the same parts as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. The hydraulic transmission 200 includes a pump 11 connected to be driven by the power source 1 via an input shaft 201, and a motor 13 connected to the pump 11 by a pipe 202, a hydraulic valve 203, and a pipe 204. From the motor 13 enters the speed increasing / reducing device 220 fixed to the intermediate shaft 205 from the motor 13. In the speed increasing / reducing device 220, a gear 221 of the speed increasing / reducing device 220, and a gear 223 rotatably inserted into the output shaft 222 and a clutch 224 fixed to the output shaft 222, or a clutch 225 fixed to the intermediate shaft 205, , The gear 22 rotatably inserted into the intermediate shaft 205
6 and the output shaft 222 via a gear 227 fixed to the output shaft 222.
Are driven to drive. Pump 11 and motor 13
Are provided with discharge volume swash plate control valves 15 and 16, and the control unit 21 changes the discharge capacity of the pump 11 and the discharge capacity of the motor 13 according to this command. The hydraulic valve 203 is provided with switching ports 203a and 203b for moving the vehicle forward and backward and a port 203c to another hydraulic actuator (C). The clutch 224 and the clutch 225 receive the hydraulic pressure of the pump 23 driven by the power source 1 via clutch pressure control valves 228 and 229 controlled by the control unit 21, and connect the clutch 224 or the clutch 225 to the output shaft 222.
To rotate. A speed sensor 22 is provided on the output shaft 222, and the number of rotations is fed back to the control unit 21. The mechanical transmission 250 includes a clutch 251 fixed to the input shaft 201, a gear 252 rotatably inserted into the input shaft 201, and an intermediate gear 253 in addition to the transmission elements such as gears provided in the first embodiment.
And a gear 254 fixed to the intermediate shaft 205. The hydraulic pressure of the pump 23 is received via the clutch pressure control valve 24 or the clutch pressure control valve 255 controlled by the control unit 21. 251
And the intermediate shaft 205 is rotated. The rotation of the intermediate shaft 205 drives the output shaft 222 via the acceleration / deceleration device 220. Input shaft
The speed sensor 25 is provided in 201 and the number of rotations is fed back to the control unit 21. The control unit 21 is provided with a switching means 206 for switching between forward and backward movement of a construction machine or the like and another hydraulic actuator such as a work machine, and a speed control means 27 such as an accelerator petal for controlling a vehicle speed.

In the above configuration, when a vehicle such as a construction machine moves forward and backward, the switching unit 206 is switched, and a signal is sent to the control unit 21 to output a signal for switching the hydraulic valve 203. The hydraulic valve 203 receives the signal and switches to the forward / backward switching port 203a or 203b of the vehicle to change the flow of oil from the pump 11 to the motor 13 to move the vehicle forward / backward. At this time, the mechanical transmission
The clutches 31 and 251 of the 250 are disengaged, and the clutch 224 or the clutch 225 of the speed increasing / reducing device 220 is connected by a command of the control unit 21 according to the rotation speed of the output shaft 222, and the power is output by the hydraulic transmission device 200 to the output shaft. Tell 222. Output shaft 222
The speed control is controlled by a signal from a speed control means 27 such as an accelerator petal or the like, and is controlled by a combination of a discharge capacity ratio of the pump 11 and the motor 13 and a gear ratio of the gears 221 and 223 or the gears 226 and 227 stored in the control unit 21. You. If the hydraulic valve 203 is set to the neutral port 203c without switching the switching means 206, power is not transmitted to the output shaft 222, and the discharge flow rate of the pump 11 can be used for another hydraulic actuator or the like. At this time, the vehicle such as the construction machine can operate the work machine by supplying the discharge flow rate of the pump 11 to the hydraulic actuator of the work machine mounted in a stopped state. In this embodiment, when the rotation speed of the pump 11 and the output shaft 222 is larger than a predetermined value, either the clutch 31 or 251 of the mechanical transmission device 250 is connected regardless of whether the rotation direction of the output shaft 222 is normal or reverse. And the clutch 224 of the
And one of the 225. Further, by setting the discharge flow rates of the pump 11 and the motor 13 to zero as in the first embodiment, the power of the power source 1 is transmitted to the output shaft 222 only through the mechanical transmission device 250 having high transmission efficiency. At this time, when the rotation speed is in a range greater than the predetermined value, the discharge flow rate of the pump 11 is set to zero, so that the working machine mounted on a vehicle such as a construction machine does not operate. Also at this time, the clutch
Whether to join either 31 or 251 is determined by a signal from the speed control means 27 such as an accelerator petal or the like, and a signal from the switching means 206 for moving the vehicle back and forth, and the clutch 31 or Join any of the 251. Although the speed sensor 22 is provided on the output shaft 222 and the number of revolutions is fed back to the control unit 21, it may be provided on the intermediate shaft 205 of the motor 13.

FIG. 4 shows a fourth embodiment of the present invention. In this figure, the same components as those of the third embodiment are denoted by the same reference numerals, and the description is omitted. The hydraulic transmission 300 includes a pump 11 connected to be driven by the power source 1 via an input shaft 201, and a third embodiment including a motor 13 connected to the pump 11 by a pipe 202, a hydraulic valve 203, and a pipe 204. In addition to the example, a hydraulic valve (D) for another hydraulic actuator (not shown) that is branched from a pipe 202 and connected to a pipe 301 and a hydraulic valve 302 for an actuator.
Oil is supplied and drained to drive. The hydraulic valve 203 is provided with switching ports 203a and 203b for moving the vehicle forward and backward and a neutral port 203c, and returns the oil to the tank 303 when the vehicle is in the neutral state.

In the above configuration, when a vehicle such as a construction machine moves forward and backward, the switching unit 206 is switched, and a signal is sent to the control unit 21 to output a signal for switching the hydraulic valve 203. The hydraulic valve 203 receives the signal and switches to the forward / backward switching port 203a or 203b of the vehicle to change the flow of oil from the pump 11 to the motor 13 to move the vehicle forward / backward. When only the other hydraulic actuator is driven, the switching means 206 is not switched and the actuator hydraulic valve 302 is operated to supply the oil of the pump 11 to the driven hydraulic actuator via the ports 302a and 302b. At this time, the switching means 20 for moving the vehicle back and forth.
By switching 6, the vehicle can move forward and backward while driving the hydraulic actuator. In the above, as in the third embodiment, when the rotation speed is in a range greater than the predetermined value, the pump
Since the discharge flow rate of 11 is set to zero, the working machine mounted on the vehicle such as a construction machine does not operate, and the hydraulic actuator pump of the working machine is in a range where the rotation speed is lower than a predetermined value.
The work machine can be operated by supplying 11 discharge flow rates.

In the third and fourth embodiments, the input shaft 201 is directly connected to the pump and the intermediate shaft 205 is directly connected to the motor, but may be connected via the clutches 112 and 114 as in the second embodiment.

In the first to fourth embodiments, a signal is sent from the control unit to the pump in accordance with a signal from a switching means such as a switching lever for switching between forward and backward movement of a construction machine or the like, so that the capacity of the pump is set in a negative range. Although the rotation direction of the output shaft is reversed in the above, the rotation may be performed by setting the capacity of the motor in a negative range. A fixed displacement hydraulic motor may be provided instead of the variable displacement hydraulic motor. Also, the gear ratio of the gear has been described for one stage or two stages, but may be multi-stage,
A planetary gear train may be used. Further, the piping to the clutch is branched, but it goes without saying that a clutch pressure control valve may be provided for each clutch. Although one or two hydraulic valves are provided between the pump and the motor, a large number of hydraulic valves may be provided, and the hydraulic circuit may use a tandem, series, parallel or composite circuit. Further, in this embodiment, only the open circuit has been described for the hydraulic circuit of the hydraulic drive device, but it goes without saying that a closed circuit may be used.

〔The invention's effect〕

As described above, according to the present invention, by switching the hydraulic circuit, the discharge flow rate of the hydraulic pump can be supplied to another actuator, so that the hydraulic energy can be used without losing extra power. . Also, connect the pump and motor directly to the prime mover, and
The device can be made smaller because it is provided side by side with the mechanical transmission. Further, the mechanical hydraulic transmission is provided with a mechanical transmission and a hydraulic transmission, and when the rotation speed of the output shaft is greater than a predetermined value, power is transmitted by the mechanical transmission to improve transmission efficiency, and In a range smaller than the value, a power transmission device that can smoothly control the output rotation speed between the forward rotation and the reverse rotation because power is transmitted by the hydraulic transmission is obtained. In addition, since a planetary gear device having a complicated mechanism is not used, an excellent effect that the structure becomes extremely simple and the entire device can be made compact and inexpensive can be obtained.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a mechanical hydraulic transmission according to a first embodiment, which is the most basic, comprising a mechanical transmission of the present invention and a hydraulic transmission. FIG. 2 is an overall configuration diagram of a mechanical hydraulic transmission of a second embodiment including a mechanical transmission and a hydraulic transmission in which a clutch device is provided on a pump drive shaft system. FIG. 3 is an overall configuration diagram of a mechanical hydraulic transmission according to a third embodiment, which excludes a mechanical transmission and a clutch device of an output shaft system of the hydraulic transmission. FIG. 4 is an overall configuration diagram of a mechanical hydraulic transmission according to another fourth embodiment in which the circuit of the pump drive system of the hydraulic transmission is an open circuit and the gear trains of the mechanical system and the hydraulic system are arranged in multiple stages. FIG. 5 is an overall configuration diagram of a mechanical hydraulic transmission showing a conventional embodiment. FIG. 6 is an overall configuration diagram of a mechanical hydraulic transmission showing a conventional embodiment. FIG. 7 is an overall configuration diagram of a mechanical hydraulic transmission showing another embodiment of the prior art. 1, power source, 2,201 input shaft, 10, 110, 110, 200, hydraulic transmission device, 11 variable displacement hydraulic pump, 13 variable displacement hydraulic motor, 32, 33, 221, 223, 225, 227, 251, 254 gears, 12, 222 …… Output shaft, 31,112,113,224,225,251 …… Clutch, 20… Control device, 21… Control unit, 22,25… Speed sensor, 26… Switching means (forward / backward) 27 …… Speed control means, 30,250 …… Machine Type transmission device, 205: Intermediate shaft, 203: Hydraulic valve, 302: Hydraulic valve for actuator, 253: Intermediate gear, 206: Switching means.

Claims (6)

(57) [Claims] An input shaft connected to a prime mover having a rotation speed control means, an output shaft arranged in parallel with the input shaft, and at least one clutch and one gear arranged between the input shaft and the output shaft. A mechanical hydraulic transmission comprising a mechanical transmission comprising a row and a hydraulic pump comprising a hydraulic pump and a hydraulic motor transmitting discharge power from the hydraulic pump to the output shaft. Mounted on a vehicle driven by a hydraulic pump of a hydraulic transmission directly or via a clutch, a hydraulic motor of a hydraulic transmission directly or via a clutch connected to an output shaft, and a mechanical hydraulic transmission Is provided between the hydraulic pump and the hydraulic motor to operate the selected working machine by receiving the hydraulic oil from the hydraulic pump, and supplies the working machine actuator with the hydraulic oil. It is made of hydraulic valves mechanical hydraulic transmission according to claim that. 2. An input shaft connected to a prime mover having rotation speed control means, an output shaft arranged in parallel with the input shaft, and at least one clutch and one gear arranged between the input shaft and the output shaft. A mechanical hydraulic transmission comprising a mechanical transmission comprising a row and a hydraulic pump comprising a hydraulic pump and a hydraulic motor transmitting discharge power from the hydraulic pump to the output shaft. Mounted on a vehicle driven by a hydraulic pump of a hydraulic transmission directly or via a clutch, a hydraulic motor of a hydraulic transmission directly or via a clutch connected to an output shaft, and a mechanical hydraulic transmission And a clutch that cuts or transmits the power from the input shaft to one gear train of the mechanical transmission. A speed sensor for detecting the rotation speed of the output shaft; and a discharge pump for the hydraulic pump and / or the hydraulic motor for outputting power to the output shaft by the hydraulic transmission when the rotation speed of the output shaft is equal to or less than a predetermined value. And output a command to disconnect the clutch to the mechanical transmission, and when the rotation speed of the output shaft is equal to or higher than a predetermined value, the power is transmitted to the output shaft by the mechanical transmission. A control means for outputting a command to connect a clutch to a mechanical transmission to output a command to minimize an absorption torque to a hydraulic pump and a hydraulic motor, and disposed between the hydraulic pump and the hydraulic motor. And a hydraulic valve for supplying hydraulic oil to an actuator of a working machine. 3. An input shaft connected to a motor having rotation speed control means, an output shaft arranged in parallel with the input shaft, and at least one clutch and one gear arranged between the input shaft and the output shaft. A mechanical hydraulic transmission comprising a mechanical transmission comprising a row and a hydraulic pump comprising a hydraulic pump and a hydraulic motor transmitting discharge power from the hydraulic pump to the output shaft. A hydraulic pump of the hydraulic transmission device connected thereto, an intermediate shaft disposed between the input shaft and the output shaft and transmitting power from a mechanical transmission device or a hydraulic motor to the output shaft, and an intermediate shaft and an output shaft. Disposed in between, a speed increasing and reducing device comprising at least one clutch and one gear train, and a hydraulic motor coupled to the intermediate shaft, and transmitting the power of the hydraulic transmission through the clutch of the speed increasing and reducing device, Machine An actuator that operates a work machine mounted on a vehicle traveling by a hydraulic transmission system by receiving pressure oil from a hydraulic pump, a speed sensor that detects a rotation speed of an output shaft, and a signal from a speed sensor of an output shaft. When the rotation speed of the output shaft is equal to or lower than a predetermined value, the power is output to the output shaft via the hydraulic transmission and the speed increase / decrease device, so that the clutch of the speed increase / decrease device disposed between the intermediate shaft and the output shaft is output. Output a command to increase or decrease the discharge volume to the hydraulic pump and the hydraulic motor, and output a command to disconnect the clutch of the mechanical transmission and connect the clutch to the clutch of the acceleration / deceleration device. When the rotation speed of the shaft is equal to or higher than a predetermined value, the power is output to the output shaft through the mechanical transmission and the speed increasing / decelerating device, so that the discharge volumes of the hydraulic pump and the hydraulic motor are reduced. And a control means for outputting a command to be engaged with a clutch of a mechanical transmission and a clutch of a speed increasing / decreasing device, and a hydraulic pressure which is disposed between a hydraulic pump and a hydraulic motor and supplies pressure oil to an actuator of a work machine. A mechanical hydraulic transmission comprising a valve. 4. The mechanical hydraulic transmission according to claim 1, wherein the hydraulic valve for the working machine for supplying hydraulic oil to the actuator of the working machine, and the hydraulic motor of the hydraulic transmission are connected to the hydraulic pump. A mechanical hydraulic transmission, which is connected in parallel. 5. The mechanical hydraulic transmission according to claim 1, wherein when the hydraulic valve supplies pressurized oil to the actuator of the working machine, the rotation speed of the output shaft is equal to or less than a predetermined value, or A mechanical hydraulic transmission, which is at zero. 6. A mechanical transmission device that receives the power of a prime mover having rotation speed control means and transmits the power to an output shaft by mechanical means, and discharge pressure oil from a hydraulic pump that receives the power of the prime mover having rotation speed control means. And a hydraulic transmission comprising a hydraulic motor for transmitting power to the output shaft upon receipt of the output shaft.The hydraulic transmission includes a hydraulic transmission, or a mechanical transmission according to the rotation speed of the output shaft. A method of controlling a mechanical hydraulic transmission that outputs to an output shaft by any of a transmission, wherein when a rotation speed of the output shaft is equal to or less than a predetermined value, a work machine mounted on a vehicle traveling by the mechanical hydraulic transmission is A method for controlling a mechanical hydraulic transmission, wherein the method is operated by hydraulic oil from a hydraulic pump of the hydraulic transmission.