JP6335870B2 - Mixer drum drive device - Google Patents

Description

  The present invention relates to a mixer drum driving device.

  Patent Document 1 describes a drum rotating device that rotationally drives a drum that is rotatably mounted on a mixer vehicle. The drum rotating device described in Patent Document 1 is connected to a hydraulic pump driven by a traveling engine of a mixer vehicle, a hydraulic motor rotated by pressure oil sent from the hydraulic pump, and an output shaft of the hydraulic motor. And a drum. In the drum rotating device described in Patent Document 1, the rotation direction of the hydraulic motor is switched in the forward direction or the reverse direction by switching the position of the switching valve by operating the switching lever.

  Patent Document 2 describes a drive device that rotationally drives a mixer drum that is mounted on a vehicle and can be loaded with ready-mixed concrete. The drive device described in Patent Document 2 includes a hydraulic pump driven by a traveling engine, a hydraulic motor that is driven by hydraulic oil discharged from the hydraulic pump to rotationally drive the mixer drum, and a switch that switches a rotation direction of the hydraulic motor. And a valve. The drive device described in Patent Document 2 is configured to drive an auxiliary hydraulic pump by an electric motor using a battery as a drive source and to operate the hydraulic motor by hydraulic oil discharged from the auxiliary hydraulic pump when idling is stopped. ing.

JP 2012-91729 A JP 2014-196094 A

  Generally, in a mixer truck, a mixer drum is rotated during traveling in order to prevent separation of ready-mixed concrete. In recent years, there has been a demand for a mixer vehicle having an idling stop function.

  When the mixer driving device described in Patent Document 1 is applied as it is to a mixer vehicle having an idling stop function, the traveling engine stops when idling stops, and therefore the hydraulic pump driven by the traveling engine also stops. . For this reason, in the mixer drive device described in Patent Document 1, the mixer drum cannot be rotated by the hydraulic pump when idling is stopped.

  Therefore, it is conceivable to provide an auxiliary hydraulic pump that is driven by an electric motor that uses a battery as a power source, as in the driving device described in Patent Document 2, and to rotate the hydraulic motor by this auxiliary hydraulic pump.

However, in the mixer driving device described in Patent Document 2 , the switching valve is maintained in the communication position during idling stop. For this reason, the hydraulic oil discharged from the auxiliary pump flows into the hydraulic pump through the switching valve, and the flow rate of the hydraulic oil discharged from the auxiliary pump may decrease. If the flow rate of the hydraulic oil discharged from the auxiliary pump in this way is reduced, the rotation of the mixer drum will be insufficient.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a mixer drum driving device capable of stably supplying the working fluid discharged from the auxiliary fluid pressure pump to the mixer drum during idling stop. .

A first invention is a mixer drum driving device that rotationally drives a mixer drum that is mounted on a vehicle and can be loaded with ready-mixed concrete, and includes a fluid pressure pump that is driven by an engine of the vehicle and a working fluid that is discharged from the fluid pressure pump. A hydraulic pressure motor that operates to rotationally drive the mixer drum; a forward rotation position that guides the working fluid discharged from the fluid pressure pump to the fluid pressure motor so as to rotate the mixer drum in a forward direction; and a working fluid discharged from the fluid pressure pump. It is manually switched between a reverse rotation position for guiding the mixer drum to the fluid pressure motor so as to reversely rotate and a blocking position for blocking the flow of the working fluid between the fluid pressure pump and the fluid pressure motor. A control valve that controls the flow of the working fluid to the fluid pressure motor and the electric valve when the engine is idling stopped A motor that is driven by the rotation of the motor by discharging a working fluid, and an auxiliary hydraulic pump for operating the hydraulic motor, when the control valve even during the idling stop is in the forward position, A backflow prevention unit that prevents backflow of the working fluid from the control valve toward the fluid pressure pump.

  In the first aspect of the invention, since the backflow prevention unit for preventing the backflow of the working fluid from the control valve toward the fluid pressure pump is provided, the working fluid discharged from the auxiliary fluid pressure pump is prevented from flowing into the fluid pressure pump side. The

The second invention, control valve is maintained in the forward position during idling stop, the engine is characterized in that it is maintained also forward position when driven again from an idling stop state.

  In the second aspect of the invention, when the engine is driven again from the idling stop state, the control valve is maintained at the normal rotation position, so that the driving by the auxiliary fluid pressure pump can be smoothly switched to the driving by the fluid pressure pump. . Thereby, since supply of the working fluid to the fluid pressure motor is not interrupted, the mixer drum can be rotated stably.

  According to a third aspect of the present invention, the backflow prevention unit is a check valve, and is provided between the fluid pressure pump and the control valve.

  In 3rd invention, it can be set as a simple structure by comprising a backflow prevention part with a check valve. In addition, since it is not necessary to control the backflow prevention unit, the control of the mixer drum driving device can be simplified.

  According to a fourth aspect of the invention, the backflow prevention unit is a check valve, and is provided in the control valve so as to function only when the control valve is in the forward rotation position.

  In 4th invention, it can be set as a simple structure by comprising a backflow prevention part with a check valve. Furthermore, since the check valve functions only when the control valve is in the forward rotation position, the check valve is not affected by pressure loss due to the check valve in the reverse rotation position. Thereby, the efficiency of a fluid pressure pump can be improved and energy saving can be achieved.

  According to a fifth aspect of the invention, the backflow prevention unit is a switching valve.

  According to a sixth aspect of the invention, the switching valve is a pilot operated switching valve that is switched by a pilot pressure supplied from an auxiliary fluid pressure pump.

  According to the present invention, it is possible to stably supply the working fluid discharged from the auxiliary fluid pressure pump to the mixer drum during idling stop.

It is a top view of the mixer truck carrying the mixer drum drive device concerning the embodiment of the present invention. 1 is a hydraulic circuit diagram of a mixer drum driving device according to an embodiment of the present invention. It is a hydraulic circuit diagram at the time of idling stop of the mixer drum driving device according to the embodiment of the present invention. It is a hydraulic circuit diagram which shows the modification of the mixer drum drive device which concerns on embodiment of this invention. It is a hydraulic circuit diagram which shows the modification of the mixer drum drive device which concerns on embodiment of this invention. It is a hydraulic circuit diagram which shows the modification of the mixer drum drive device which concerns on embodiment of this invention.

  Hereinafter, a mixer drum driving apparatus 100 according to an embodiment of the present invention will be described with reference to the drawings.

  First, with reference to FIG. 1, an overall configuration of the mixer truck 10 on which the mixer drum driving device 100 is mounted will be described.

  The mixer vehicle 10 includes a traveling engine 3 of the vehicle 1, a mixer drum 2 mounted on the vehicle 1 and capable of loading ready-mixed concrete, and a mixer drum driving device 100 that rotationally drives the mixer drum 2. The mixer truck 10 transports ready-mixed concrete loaded in the mixer drum 2.

  The mixer drum 2 is a bottomed cylindrical container that is rotatably mounted on the vehicle 1. The mixer drum 2 is mounted such that the rotating shaft faces the front-rear direction of the vehicle 1. The mixer drum 2 is mounted so as to be inclined forward and backward so as to gradually increase toward the rear portion of the vehicle 1. The mixer drum 2 has an opening at its rear end, and ready concrete can be charged and discharged from the opening.

  The mixer drum 2 is supported on the vehicle 1 at three points: a front part to which the output shaft of the mixer drum driving device 100 is connected and a left and right part of the rear part. The rear part of the mixer drum 2 is rotatably supported by rollers (not shown). The mixer drum 2 is rotationally driven using the traveling engine 3 as a power source.

  Next, the mixer drum driving apparatus 100 will be described with reference to FIGS. 2 and 3. FIG. 2 is a diagram illustrating a hydraulic circuit of the mixer drum driving device 100.

  The mixer drum driving device 100 is driven by the rotation of the traveling engine 3 and rotationally drives the mixer drum 2 by the fluid pressure of the working fluid. The rotational movement of the crankshaft in the traveling engine 3 is transmitted to the mixer drum driving device 100 by a power take-off mechanism 4 (PTO: Power-take-off) for constantly taking out the power from the traveling engine 3.

  In the mixer drum driving apparatus 100, hydraulic oil is used as the working fluid. Other incompressible fluids may be used as the working fluid instead of the working oil. The mixer drum driving device 100 includes a hydraulic pump 5 as a fluid pressure pump driven by the traveling engine 3, and a hydraulic motor as a fluid pressure motor that is driven by hydraulic oil discharged from the hydraulic pump 5 to rotationally drive the mixer drum 2. 6, a control valve 8 that controls the flow of hydraulic oil from the hydraulic pump 5 to the hydraulic motor 6, a charge pump 9 that is driven by the traveling engine 3 and is provided coaxially with the hydraulic pump 5, and the hydraulic pump 5 and the control valve And a check valve 14 serving as a backflow prevention unit that prevents backflow of hydraulic oil from the control valve 8 toward the hydraulic pump 5.

  The hydraulic pump 5 is rotationally driven by the power that is always extracted from the traveling engine 3 via the power extraction mechanism 4. The hydraulic pump 5 is a swash plate type axial piston pump having a variable capacity.

  The hydraulic motor 6 is a swash plate type axial piston motor having a fixed capacity. The hydraulic motor 6 is rotationally driven in response to the supply of hydraulic oil discharged from the hydraulic pump 5. The mixer drum 2 is connected to the hydraulic motor 6 via a speed reducer 7. The hydraulic motor 6 is switched to normal rotation or reverse rotation by the control valve 8. When the mixer drum 2 is rotated forward by the hydraulic motor 6, the ready-mixed concrete in the mixer drum 2 is agitated. On the other hand, when the mixer drum 2 is rotated reversely by the hydraulic motor 6, the ready-mixed concrete in the mixer drum 2 is discharged to the outside from the opening at the rear end. In the present embodiment, the hydraulic motor 6 is described as a swash plate type axial piston motor having a fixed capacity. However, the hydraulic motor 6 is not limited to this, and the hydraulic motor 6 has a variable capacity. It may be.

  A closed circuit 20 is provided between the hydraulic pump 5 and the hydraulic motor 6, and hydraulic oil circulates through the closed circuit 20. The closed circuit 20 includes a return passage (pump suction passage) 21 that connects the suction port of the hydraulic pump 5 and the control valve 8, and a supply passage (pump discharge passage) that connects the discharge port of the hydraulic pump 5 and the control valve 8. 22, and first and second supply / discharge passages 23 and 24 that connect the control valve 8 and each of two ports provided in the hydraulic motor 6.

  The control valve 8 directs the hydraulic oil discharged from the hydraulic pump 5 to the hydraulic motor 6 so as to rotate the mixer drum 2 in the forward direction and the hydraulic oil discharged from the hydraulic pump 5 to reversely rotate the mixer drum 2. A reverse rotation position B leading to the hydraulic motor 6 and a blocking position C for blocking the flow of hydraulic oil from the hydraulic pump 5 to the hydraulic motor 6 are provided. The control valve 8 is switched when the driver operates the operation lever 8a.

  The charge pump 9 discharges hydraulic oil sucked from the tank T through the passage 25 to the charge passage 26. This hydraulic oil is charged into the return passage 21 from the charge passage 26 through the check valve 15.

  The charge passage 26 communicates with the tank T through the relief valve 50. When the pressure in the charge passage 26 rises above a predetermined value, the relief valve 50 is opened, and excess hydraulic oil discharged from the charge pump 9 is returned to the tank T.

  The check valve 14 is provided in the supply passage 22 that connects the hydraulic pump 5 and the control valve 8 so as to prevent backflow of hydraulic oil from the control valve 8 toward the discharge port side of the hydraulic pump 5.

  The mixer drum driving apparatus 100 is a load sensing valve that adjusts so that a differential pressure between a load pressure generated in one of the first and second supply / discharge passages 23 and 24 and a pressure (pump discharge pressure) in the supply passage 22 becomes a predetermined value. 30 and a cutoff valve 40 that adjusts the pump discharge capacity of the hydraulic pump 5 in accordance with the pressure of the supply passage 22 (pump discharge pressure).

  A load pressure generated in one of the first and second supply / discharge passages 23 and 24 and a pump discharge pressure in the supply passage 22 are guided to the load sensing valve 30 as pilot pressures. The load sensing valve 30 adjusts the pilot pressure guided to the actuator 5a via the actuator passage 27 so that these differential pressures become a predetermined value.

  The load sensing valve 30 includes a position F that communicates the actuator 5 a with the tank T, and a position G that communicates the actuator 5 a with the supply passage 22. The load sensing valve 30 is constantly biased to the position F by the biasing force of the spring 34.

  First and second pilot pressure passages 31 and 32 are connected to the load sensing valve 30. The first pilot pressure passage 31 communicates with the high pressure side (load pressure side) of the first and second supply / discharge passages 23 and 24 via the high pressure selection valve 33. The second pilot pressure passage 32 is connected to the supply passage 22. As the high pressure selection valve 33, for example, a shuttle valve is used.

  In the load sensing valve 30, the load pressure guided from the first pilot pressure passage 31 works in the direction of switching to the position F together with the urging force of the spring 34, and the pressure in the supply passage 22 led from the second pilot pressure passage 32 (pump discharge Pressure) acts in the direction of switching to the position G against the load pressure guided from the first pilot pressure passage 31 and the urging force of the spring 34.

  The cut-off valve 40 is guided with the pressure of the supply passage 22 (pump discharge pressure) as a pilot pressure. The cut-off valve 40 increases the pilot pressure guided to the actuator 5a when the pump discharge pressure rises above a predetermined value, thereby reducing the pump discharge capacity of the hydraulic pump 5.

  The cut-off valve 40 includes a position H that communicates the actuator 5 a with the tank T, and a position I that communicates the actuator 5 a with the supply passage 22.

  A pilot pressure passage 41 of the cutoff valve 40 is connected to the supply passage 22. The cut-off valve 40 works in the direction in which the urging force of the spring 42 is switched to the position H, and the pilot pressure (pump discharge pressure) guided from the pilot pressure passage 41 is switched to the position I against the urging force of the spring 42. work.

  When the mixer drum 2 is driven, the cut-off valve 40 is held at the position H when the pressure in the supply passage 22 (pump discharge pressure) is equal to or lower than a predetermined value, and the actuator passage 27 connecting the load sensing valve 30 and the actuator 5a is opened. . In this state, a load pressure generated in one of the first and second supply / discharge passages 51 and 52 and a pressure in the supply passage 22 (pump discharge pressure) are guided to the load sensing valve 30 as pilot pressures. . The load sensing valve 30 adjusts the pressure of the actuator passage 27 guided to the actuator 5a according to these differential pressures. As a result, the pump discharge capacity of the hydraulic pump 5 has a predetermined differential pressure between the load pressure generated in one of the first and second supply / discharge passages 23 and 24 and the pressure of the supply passage 22 (pump discharge pressure) by the actuator 5a. Adjusted to a value.

  When the drive of the mixer drum 2 is stopped, the control valve 8 is switched to the cutoff position C, and the communication between the supply passage 22 and the first and second supply / discharge passages 23 and 24 is cut off. At this time, if the pump discharge pressure increases beyond a predetermined value, the pilot pressure (pump discharge pressure) guided from the pilot pressure passage 41 increases, so that the cutoff valve 40 is positioned against the biasing force of the spring 42. Switch from H to position I. As a result, the actuator 5a communicates with the supply passage 22, so that the pressure (pump discharge pressure) in the supply passage 22 is guided to the actuator 5a, and the pump discharge capacity of the hydraulic pump 5 is reduced.

  The mixer drum driving device 100 includes an electric motor 11 driven by electric power stored in a battery (not shown), an auxiliary hydraulic pressure as an auxiliary fluid pressure pump that is driven by the rotation of the electric motor 11 to discharge hydraulic oil and operate the hydraulic motor 6. The pump 12 further includes an opening / closing valve 13 provided in a discharge passage 29 that connects the second supply / discharge passage 24 and the tank T to open and close the discharge passage 29.

  The output shaft of the electric motor 11 is connected to the rotation shaft of the auxiliary hydraulic pump 12. The electric motor 11 is driven when the idling of the traveling engine 3 is stopped, that is, when idling is stopped, and drives the auxiliary hydraulic pump 12.

  The auxiliary hydraulic pump 12 sucks the hydraulic oil stored in the tank T and discharges it to the auxiliary supply passage 28. The hydraulic oil discharged to the auxiliary supply passage 28 is supplied to the first supply / discharge passage 23 through the check valve 16. As a result, the hydraulic oil discharged from the auxiliary hydraulic pump 12 is supplied to the hydraulic motor 6 through the auxiliary supply passage 28 and the first supply / discharge passage 23 to cause the hydraulic motor 6 to rotate forward.

  The electric motor 11 and the auxiliary hydraulic pump 12 are for rotating the mixer drum 2 so that the stirring of the ready-mixed concrete loaded on the mixer drum 2 does not stop when the traveling engine 3 stops idling.

  The on-off valve 13 is an electromagnetic switching valve controlled by a controller (not shown). The on-off valve 13 includes a position D that blocks communication between the second supply / discharge passage 24 and the tank T, and a position E that connects the second supply / discharge passage 24 and the tank T. The on-off valve 13 is normally biased by a spring so as to maintain the D position. The on-off valve 13 is switched to the E position by applying a current by the controller when idling is stopped.

  The operation of the mixer drum driving apparatus 100 configured as described above will be described.

  When the traveling engine 3 is driven, the hydraulic pump 5 is driven and hydraulic oil is discharged into the supply passage 22. During transportation of the ready-mixed concrete, the driver operates the operation lever 8a to switch the control valve 8 from the shut-off position C to the normal rotation position A. Accordingly, the hydraulic oil discharged to the supply passage 22 is supplied to the hydraulic motor 6 through the check valve 14, the control valve 8, and the first supply / discharge passage 23, and the hydraulic motor 6 is rotated forward.

  The rotation of the hydraulic motor 6 is transmitted to the mixer drum 2 via the speed reducer 7 and causes the mixer drum 2 to rotate forward. Thereby, the ready-mixed concrete in the mixer drum 2 is stirred. The hydraulic oil discharged from the hydraulic motor 6 is returned to the suction port of the hydraulic pump 5 through the second supply / discharge passage 24, the control valve 8, and the return passage 21.

  In this way, the mixer drum 2 is rotated forward by switching the control valve 8 to the normal rotation position A while the traveling engine 3 is driven. Thereby, the ready-mixed concrete is agitated in the mixer drum 2 and is prevented from being separated.

  When the driver operates the operation lever 8a and switches the control valve 8 from the shut-off position C to the reverse rotation position B while the traveling engine 3 is being driven, the hydraulic oil discharged to the supply passage 22 is supplied to the check valve 14 and the control valve. It is supplied to the hydraulic motor 6 through the valve 8 and the second supply / exhaust passage 24 to rotate the hydraulic motor 6 in the reverse direction. The rotation of the hydraulic motor 6 is transmitted to the mixer drum 2 via the speed reducer 7 and rotates the mixer drum 2 in the reverse direction. Thereby, the ready-mixed concrete in the mixer drum 2 is discharged | emitted from the opening part of a rear end to the exterior. The hydraulic oil discharged from the hydraulic motor 6 is returned to the suction port of the hydraulic pump 5 through the first supply / discharge passage 23, the control valve 8, and the return passage 21.

  When the mixer drum 2 (hydraulic motor 6) is driven to rotate and the pressure in the supply passage 22 (pump discharge pressure) is below a predetermined value, the cut-off valve 40 is held at the position H and connects the load sensing valve 30 and the actuator 5a. The actuator passage 27 is opened. The load sensing valve 30 is connected from the supply passage 22 to the actuator passage so that a differential pressure between the load pressure generated in one of the first and second supply / discharge passages 23 and 24 and the pressure of the supply passage 22 (pump discharge pressure) becomes a predetermined value. The pressure guided to the actuator 5a via 27 is adjusted. As a result, the pump discharge capacity of the hydraulic pump 5 has a predetermined differential pressure between the load pressure generated in one of the first and second supply / discharge passages 23 and 24 and the pressure of the supply passage 22 (pump discharge pressure) by the actuator 5a. Adjusted to a value.

  When the mixer vehicle 10 is stopped by a signal or the like while traveling, the traveling engine 3 is stopped idling and enters an idling stop state. In this way, when the traveling engine 3 stops, the hydraulic pump 5 also stops rotating, so that the hydraulic motor 6 cannot be driven to rotate by the hydraulic pump 5. At this time, the auxiliary hydraulic pump 12 is driven by the electric motor 11 using the battery as a power source, and the hydraulic oil is supplied to the first supply / discharge passage 23 through the auxiliary supply passage 28. As a result, the hydraulic oil discharged from the auxiliary hydraulic pump 12 is supplied to the hydraulic motor 6 through the auxiliary supply passage 28 and the first supply / discharge passage 23 to rotate the hydraulic motor 6 in the normal direction. At the same time, a current is applied to the on-off valve 13 from a controller (not shown), and the on-off valve 13 is switched to the position E (see FIG. 3). As a result, the hydraulic oil discharged from the hydraulic motor 6 is returned to the tank T through the second supply / discharge passage 24, the discharge passage 29, and the on-off valve 13.

  At this time, as shown in FIG. 3, since the control valve 8 is maintained in the forward rotation position A, the hydraulic oil discharged from the auxiliary hydraulic pump 12 causes the control valve 8 to move as shown by the arrow in FIG. It flows into the supply passage 22 through. However, since the check valve 14 is provided in the supply passage 22, the hydraulic oil discharged from the auxiliary hydraulic pump 12 is prevented from flowing into the hydraulic pump 5. Therefore, it is possible to prevent the hydraulic oil discharged from the auxiliary hydraulic pump 12 from flowing into the hydraulic pump 5, and thus the flow rate of the hydraulic oil discharged from the auxiliary hydraulic pump 12 can be prevented. Therefore, the rotation of the mixer drum 2 during the idling stop can be prevented. Can be prevented.

  When the idling stop state is released, for example, when the driver depresses the accelerator pedal, the traveling engine 3 is driven again. As a result, the hydraulic pump 5 is rotationally driven and discharges hydraulic oil to the supply passage 22. At the same time, the electric motor 11 is stopped and application of current from the controller to the on-off valve 13 is stopped. When the electric motor 11 is stopped, the supply of hydraulic oil from the auxiliary hydraulic pump 12 to the auxiliary supply passage 28 is stopped. Further, when the application of current from the controller is stopped, the on-off valve 13 is switched to the position D, so that the communication between the second supply / discharge passage 24 and the tank T is interrupted.

  In this way, the hydraulic motor 6 is rotationally driven by the hydraulic oil discharged from the hydraulic pump 5 again.

  According to the mixer drum driving device 100 described above, the following effects can be obtained.

  The mixer drum driving device 100 includes a check valve 14 that prevents backflow of hydraulic oil from the control valve 8 toward the hydraulic pump 5. This prevents the hydraulic oil discharged from the auxiliary hydraulic pump 12 from flowing into the hydraulic pump 5 side when idling is stopped. Accordingly, since the hydraulic oil discharged from the auxiliary hydraulic pump 12 can be stably supplied to the mixer drum 2 during idling stop, it is possible to prevent the rotation of the mixer drum 2 from being insufficient.

  When the mixer drum driving device 100 does not include the check valve 14, the control valve 8 is switched from the normal rotation position A to the cutoff position C each time the idling stop state is switched, so that the auxiliary hydraulic pump 12 and the supply passage 22 communicate with each other. It is necessary to shut off. In particular, when the control valve 8 is a manual operation type, switching the control valve 8 to the cutoff position C every idling stop is a great burden on the driver.

  Since the mixer drum driving device 100 includes the check valve 14, it is not necessary to switch the control valve 8 to the cutoff position C even when the mixer drum driving device 100 is switched to the idling stop state. That is, it is possible to prevent the hydraulic oil discharged from the auxiliary hydraulic pump 12 from flowing into the hydraulic pump 5 even when the control valve 8 is maintained at the normal rotation position A when idling is stopped. Therefore, the work of switching the control valve 8 can be made unnecessary.

  Further, by adopting the check valve 14 as the backflow prevention unit, it can be configured with a simple structure. Furthermore, since the check valve 14 does not need to be controlled, it is not necessary to provide a control signal or piping. Therefore, the mixer drum driving device 100 can be made a simple structure.

  If the control valve 8 is switched from the forward rotation position A to the cutoff position C when idling is stopped, the control valve 8 is moved from the cutoff position C to the forward rotation position A when the traveling engine 3 is driven again from the idling stop state. Therefore, there is a time lag when switching from driving by the auxiliary hydraulic pump 12 to driving by the hydraulic pump 5. However, in the mixer drum driving apparatus 100, when the traveling engine 3 is driven again from the idling stop state, the control valve 8 is maintained at the normal rotation position A, and therefore it is not necessary to switch the control valve 8. Therefore, it is possible to smoothly switch from driving by the auxiliary hydraulic pump 12 to driving by the hydraulic pump 5. Thereby, since the supply of the hydraulic oil to the hydraulic motor 6 is not interrupted, the mixer drum 2 can be rotated stably.

  The control valve 8 has been described as an example of a manual type switching means, but may be an electromagnetically operated type. Even in this case, since the control valve 8 may be maintained at the normal rotation position A when idling is stopped, control for switching the control valve 8 to the cutoff position C can be made unnecessary. Therefore, control can be simplified.

  The check valve 14 is provided between the hydraulic pump 5 and the control valve 8. However, as shown in FIG. 4, the check valve 14 functions only when the control valve 8 is in the forward rotation position A. It may be provided inside. Thus, when the control valve 8 is in the forward rotation position A, the check valve 14 functions to prevent backflow of hydraulic oil from the control valve 8 toward the hydraulic pump 5, and the control valve 8 is in the reverse rotation position B. At times, the check valve 14 does not function. More specifically, the mixer drum 2 is not normally rotated reversely while the mixer vehicle 10 is traveling. That is, since the control valve 8 is not switched to the reverse rotation position B when idling is stopped (during traveling), it is not necessary to consider the backflow of hydraulic oil from the control valve 8 to the hydraulic pump 5 at the reverse rotation position B. There is no effect. Further, when the mixer drum 2 is rotated reversely (for example, when the control valve 8 is in the reverse rotation position B) while the mixer vehicle 10 is stopped, the hydraulic oil discharged from the hydraulic pump 5 is affected by the pressure loss caused by the check valve 14. It is supplied to the hydraulic motor 6 without receiving. Therefore, by adopting such a configuration, when the mixer drum 2 is rotated in the reverse direction, it is not affected by the pressure loss of the check valve 14, so that the efficiency of the hydraulic pump 5 can be improved and energy saving can be achieved. .

  In the above embodiment, the check valve 14 is described as an example of the backflow prevention unit. However, as shown in FIG. 5, an electromagnetic switching valve 60 may be employed as the backflow prevention unit. In this case, the on-off valve 13 and the electromagnetic switching valve 60 are controlled in synchronization to function in the same manner as when the check valve 14 is employed.

  Further, as shown in FIG. 6, a pilot operated switching valve 160 may be employed as the backflow prevention unit. Hereinafter, a modification using the pilot operated switching valve 160 will be described.

  In this modification, a pilot operated switching valve 160 is provided in the supply passage 22 instead of the check valve 14, and an opening / closing valve 113 is provided in the discharge passage 29 instead of the opening / closing valve 13.

  The pilot operated switching valve 160 includes a position J that opens the supply passage 22 and a position K that blocks the supply passage 22. Pilot operated switching valve 160 is configured as a normally open type. Specifically, when the pilot pressure is not acting on the pilot chamber 160a, it is held at the position J by the biasing force of the spring 160b, and when the pilot pressure is acting on the pilot chamber 160a, it resists the biasing force of the spring 160b. Then, the valve body is moved and switched to the position K. Pilot pressure is supplied to the pilot chamber 160a through a pilot passage 161 branched from the upstream side of the check valve 16 in the auxiliary supply passage.

  A pilot pressure discharge passage 162 that branches from the auxiliary supply passage 28 and communicates with the tank T is connected to the on-off valve 113. The on-off valve 113 is an electromagnetic switching valve that is controlled in the same manner as the on-off valve 13 by a controller (not shown). The on-off valve 113 shuts off the second supply / discharge passage 24 and the tank T and communicates the auxiliary supply passage 28 and the tank T with each other, and communicates the second supply / discharge passage 24 and the tank T with auxiliary supply. A position E1 that blocks the passage 28 and the tank T.

  When the engine is driven, since no current is applied to the on-off valve 113, the on-off valve 113 is held at the D1 position by the biasing force of the spring. In this state, since the auxiliary hydraulic pump 12 is stopped, the hydraulic oil in the pilot chamber 160a is discharged to the tank T through the pilot passage 161, the pilot pressure discharge passage 162, and the on-off valve 113. Thereby, the pilot operated switching valve 160 is held at the position J, and the supply passage 22 is maintained in an opened state. On the other hand, when idling is stopped (when the engine is stopped), a current is applied to the on-off valve 113 by the controller, and the on-off valve 113 is switched to the E1 position. In this state, since the auxiliary hydraulic pump 12 is driven, the hydraulic oil discharged from the auxiliary hydraulic pump 12 is supplied to the pilot chamber 160a through the pilot passage 161. As a result, the pilot operated switching valve 160 is switched to the position K, and the supply passage 22 is shut off. By controlling the pilot operated switching valve 160 in this way, the pilot operated switching valve 160 functions in the same manner as the check valve 14, and the hydraulic oil discharged from the auxiliary hydraulic pump 12 when idling stops is on the hydraulic pump 5 side. Can be prevented from flowing into.

  The configuration, operation, and effect of the embodiment of the present invention configured as described above will be described together.

  The mixer drum driving device 100 is operated by a fluid pressure pump (hydraulic pump 5) driven by the engine (traveling engine 3) of the vehicle 1 and the working fluid discharged from the fluid pressure pump (hydraulic pump 5). A hydraulic pressure motor (hydraulic motor 6) for rotating the motor, a control valve 8 for controlling the flow of the working fluid from the fluid pressure pump (hydraulic pump 5) to the fluid pressure motor (hydraulic motor 6), and an engine (traveling engine) 3) an electric motor 11 that is rotated by electric power when idling is stopped, and an auxiliary fluid pressure pump (auxiliary hydraulic pump 12) that is driven by the rotation of the electric motor 11 to discharge the working fluid and operate the fluid pressure motor (hydraulic motor 6). , A backflow prevention unit (check valve 14, electric A switching valve 60), characterized in that it comprises a.

  According to this configuration, the backflow prevention unit (the check valve 14 and the electromagnetic switching valve 60) for preventing the backflow of the working fluid from the control valve 8 toward the fluid pressure pump (hydraulic pump 5) is provided. The working fluid discharged from the auxiliary hydraulic pump 12) is prevented from flowing into the fluid pressure pump (hydraulic pump 5) side. Thereby, it is possible to prevent the rotation of the mixer drum 2 from being insufficient.

  Further, in the mixer drum driving apparatus 100, the control valve 8 directs the working fluid discharged from the fluid pressure pump (hydraulic pump 5) to the fluid pressure motor (hydraulic motor 6) so as to rotate the mixer drum 2 in the forward direction. And a reverse rotation position B for guiding the working fluid discharged from the fluid pressure pump (hydraulic pump 5) to the fluid pressure motor (hydraulic motor 6) so as to reversely rotate the mixer drum 2, and fluid from the fluid pressure pump (hydraulic pump 5). The control valve 8 is maintained at the forward rotation position A when idling is stopped. The shutoff position C blocks the flow of the working fluid to the pressure motor (hydraulic motor 6).

  According to this configuration, when the engine (traveling engine 3) is driven again from the idling stop state, the control valve 8 is maintained at the normal rotation position A, so that it is driven by the auxiliary fluid pressure pump (auxiliary hydraulic pump 12). Can be smoothly switched to driving by a fluid pressure pump (hydraulic pump 5). Thereby, since supply of the working fluid to the fluid pressure motor (hydraulic motor 6) is not interrupted, the mixer drum 2 can be stably rotated.

  Further, the mixer drum driving device 100 is characterized in that the backflow prevention unit is the check valve 14 and is provided between the fluid pressure pump (hydraulic pump 5) and the control valve 8.

  According to this configuration, by configuring the backflow prevention unit with the check valve 14, a simple structure can be achieved. In addition, since it is not necessary to control the backflow prevention unit, the control of the mixer drum driving device 100 can be simplified.

  Further, the mixer drum driving device 100 is characterized in that the backflow prevention unit is the check valve 14 and is provided in the control valve 8 so as to function only when the control valve 8 is in the forward rotation position A.

  According to this configuration, by configuring the backflow prevention unit with the check valve 14, a simple structure can be achieved. Further, since the check valve 14 functions only when the control valve 8 is in the forward rotation position A, the check valve 14 is not affected by the pressure loss due to the check valve 14 in the reverse rotation position B. Thereby, the efficiency of the fluid pressure pump (hydraulic pump 5) can be improved and energy saving can be achieved.

  The mixer drum driving apparatus 100 is characterized in that the backflow prevention unit is a switching valve (electromagnetic switching valve 60, pilot operated switching valve 160).

  In the mixer drum driving apparatus 100, the switching valve (pilot operation type switching valve 160) is a pilot operation type switching valve (pilot operation type switching) that is switched by the pilot pressure supplied from the auxiliary fluid pressure pump (auxiliary hydraulic pump 12). Valve 160).

  As mentioned above, although embodiment of this invention was described, the said embodiment showed only a part of application example of this invention, and the meaning which limits the technical scope of this invention to the specific structure of the said embodiment. Absent.

  In the above embodiment, the hydraulic pump 5 is configured to be driven by the traveling engine 3, but the hydraulic pump 5 may be configured to be driven by an engine different from the traveling engine 3. Good.

  The electromagnetic switching valve 60 and the pilot operated switching valve 160 may be provided between the junction point of the first supply / discharge passage 23 with the auxiliary supply passage 28 and the control valve 8. Further, the electromagnetic switching valve 60 and the pilot operated switching valve 160 are provided in the control valve 8 so as to function only when the control valve 8 is in the forward rotation position A, as in the modification shown in FIG. Also good.

DESCRIPTION OF SYMBOLS 100 ... Mixer drum drive device, 1 ... Vehicle, 2 ... Mixer drum, 3 ... Engine for driving, 5 ... Hydraulic pump (fluid pressure pump), 6 ... Hydraulic motor (fluid pressure motor) ), 8 ... Control valve, 10 ... Mixer wheel, 11 ... Electric motor, 12 ... Auxiliary hydraulic pump (auxiliary fluid pressure pump), 13 ... Open / close valve, 14 ... Check valve ( Back flow prevention unit), 22 ... supply passage, 23 ... first supply / discharge passage, 24 ... second supply / discharge passage, 30 ... load sensing valve, 40 ... cutoff valve, 60. ..Electromagnetic switching valve (backflow prevention part), 113 ... Open / close valve, 160 ... Pilot operated switching valve (backflow prevention part)

Claims (8)

A mixer drum driving device that rotationally drives a mixer drum mounted on a vehicle and capable of loading ready-mixed concrete,
A fluid pressure pump driven by the vehicle engine;
A fluid pressure motor that is driven by the working fluid discharged from the fluid pressure pump to rotationally drive the mixer drum;
A forward rotation position for guiding the working fluid discharged from the fluid pressure pump to the fluid pressure motor so as to rotate the mixer drum in a forward direction; and a working position discharged from the fluid pressure pump to reversely rotate the mixer drum. The fluid pressure motor is manually switched between a reverse rotation position leading to the fluid pressure motor and a blocking position for blocking the flow of the working fluid between the fluid pressure pump and the fluid pressure motor. A control valve for controlling the flow of the working fluid to
An electric motor that rotates by electric power when idling stop of the engine;
An auxiliary fluid pressure pump that is driven by the rotation of the electric motor to discharge the working fluid and operate the fluid pressure motor;
A backflow prevention unit that prevents backflow of the working fluid from the control valve toward the fluid pressure pump when idling is stopped and the control valve is in the forward rotation position ;
A mixer drum driving device comprising: Before SL control valve, wherein is maintained in the forward rotation position when idling stop, the engine is as claimed in claim 1, characterized in that it is maintained in the forward position even when driving again from an idling stop state Mixer drum drive device.   The mixer drum driving device according to claim 1, wherein the backflow prevention unit is a check valve and is provided between the fluid pressure pump and the control valve. The backflow prevention unit is a check valve, the mixer drum driving apparatus according to claim 1 or 2, wherein the control valve is characterized in that provided in the control valve to function only when in the forward position .   The mixer drum driving apparatus according to claim 1, wherein the backflow prevention unit is a switching valve.   6. The mixer drum driving device according to claim 5, wherein the switching valve is a pilot operated switching valve that is switched by a pilot pressure supplied from the auxiliary fluid pressure pump.   A closed circuit is provided between the fluid pressure pump and the fluid pressure motor,
  The closed circuit includes a supply passage that connects the discharge port of the fluid pressure pump and the control valve, a return passage that connects the suction port of the fluid pressure pump and the control valve, and the control valve performs the normal rotation. A first supply / discharge passage connected to the supply passage and one port of the fluid pressure motor when in the position, and a return passage and the other port of the fluid pressure motor when the control valve is in the forward rotation position. A second supply / exhaust passage to be connected,
  An auxiliary supply passage connecting the auxiliary fluid pressure pump and the first supply / discharge passage is provided;
  The mixer drum according to any one of claims 1 to 6, wherein the backflow prevention unit is provided on the fluid pressure pump side with respect to a junction of the auxiliary supply passage and the first supply / discharge passage. Drive device.   A tank for storing a working fluid;
  An opening / closing valve provided in a discharge passage connecting the second supply / discharge passage and the tank, and opening and closing the discharge passage;
  8. The mixer drum driving device according to claim 7, wherein the on-off valve blocks the discharge passage in a normal state and opens the discharge passage at an idling stop.