JP2016068535A - Mixer truck - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mixer truck which facilitates management of a replacement time of a consumable supply.SOLUTION: A mixer truck 100 comprising a mixer drum 2 capable of mounting ready mixed concrete thereon, and blades 13, 14 for pressing the ready mixed concrete to the inside of the mixer drum 2, further comprises: a drive unit 4 for rotating and driving the mixer drum 2; and a controller 10 for controlling rotation speed of the mixer drum 2. The controller 10 comprises: a rotation position determination part 10A for determining that the blades 13, 14 have arrived at predetermined rotation positions; and a rotation speed control part 10B for reducing rotation speed of the mixer drum 2 relative to normal rotation speed, based on the determination result of the rotation position determination part 10A.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a mixer truck capable of mounting ready-mixed concrete.

  In Patent Document 1, a rotating drum that is rotatably mounted on a vehicle body, a hopper that guides the ready-mixed concrete that is put into the entrance and exit of the rotating drum, and the ready-mixed concrete that is discharged from the entrance and exit of the rotating drum are received and discharged to the outside. There is disclosed a mixer vehicle including a discharge chute.

  The mixer vehicle has a spiral blade protruding from the inner wall of the rotating drum. When discharging the ready-mixed concrete, the rotating drum rotates in one direction, and the blade pushes the ready-mixed concrete to the entrance / exit.

JP2012-228830A

  However, such a conventional mixer vehicle has a problem that the amount of ready-mixed concrete pushed out by the rotating blades periodically increases and decreases during the discharge operation of discharging ready-mixed concrete from the opening of the rotating drum. It was.

  This invention is made | formed in view of said problem, and it aims at providing the mixer truck which can suppress that the discharge amount of ready-mixed concrete increases / decreases periodically.

  The present invention provides a mixer vehicle that includes a mixer drum that can be loaded with ready-mixed concrete and includes a blade that pushes ready-mixed concrete inside the mixer drum, and includes a drive device that rotationally drives the mixer drum and a controller that controls the rotational speed of the mixer drum. The controller includes a rotational position determination unit that determines that the blade has reached a predetermined rotational position, a rotational speed control unit that lowers the rotational speed of the mixer drum from the normal rotational speed based on the determination result of the rotational position determination unit, It is characterized by providing.

  In the present invention, during the operation of discharging the ready-mixed concrete from the mixer drum, the controller lowers the rotating speed of the mixer drum from the normal rotating speed in accordance with the rotating position of the blade, so that the discharged amount of the ready-mixed concrete pushed out by the rotating blade is cycled. Increase / decrease.

It is a top view of the mixer truck concerning a 1st embodiment of the present invention. It is a side view of a mixer car. It is a control block diagram which shows the structure of a mixer vehicle. It is a characteristic view which shows the relationship between the rotation angle of the mixer drum which concerns on the mixer truck as a comparative example, and the discharge amount of ready-mixed concrete. It is a timing chart which shows the control contents of the controller concerning a 1st embodiment of the present invention. It is a control block diagram which shows the structure of the mixer truck which concerns on 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
With reference to FIG. 1A and FIG. 1B, the whole structure of the mixer vehicle 100 is demonstrated.

  The mixer vehicle 100 is a vehicle including a cab 11 and a gantry 1. The mixer vehicle 100 includes a mixer drum 2 that is mounted on the gantry 1 and can be loaded with ready-mixed concrete, a drive device 4 that rotationally drives the mixer drum 2, and a controller 10 that controls the rotation of the mixer drum 2. The mixer truck 100 carries the ready-mixed concrete in the mixer drum 2 and carries it. In addition, illustration of the drive device 4 etc. is abbreviate | omitted in FIG. 1B.

  The mixer drum 2 is a bottomed cylindrical container that is rotatably mounted on the gantry 1 and has an opening 2A at the rear end thereof. The mixer drum 2 is mounted with an inclination so that the rotation axis O gradually increases from the front to the rear of the vehicle.

  A hopper 16 is provided at the upper rear portion of the opening 2 </ b> A of the mixer drum 2. The ready-mixed concrete introduced from the opening 2A is guided to the opening 2A by the hopper 16. A flow guide 17 and a chute 18 are provided in the lower rear part of the opening 2 </ b> A of the mixer drum 2. The ready-mixed concrete discharged from the opening 2A is guided to the chute 18 by the flow guide 17 and discharged in a predetermined direction by the chute 18.

  Inside the mixer drum 2, strip-shaped first and second blades 13 and 14 projecting from the inner wall and extending in a spiral shape are provided. The first and second blades 13 and 14 are arranged so as to have a phase difference of 180 degrees with respect to the rotation center axis O.

  When the ready-mixed concrete is charged into the mixer drum 2 and stirred and kneaded, forward rotation is performed to rotate the mixer drum 2 in the clockwise direction when viewed from the rear (right end side in FIG. 1B). The ready-mixed concrete in the mixer drum 2 is sent from the rear of the mixer drum 2 to the front (from right to left in FIG. 1B) by the rotating first and second blades 13 and 14. Thereby, stirring and kneading | mixing of ready-mixed concrete are performed and the solidification is prevented.

  When the ready-mixed concrete is discharged to the mixer drum 2, reverse rotation driving is performed to rotate the mixer drum 2 counterclockwise as viewed from the rear. The ready-mixed concrete in the mixer drum 2 is fed from the front of the mixer drum 2 to the rear (left to right in FIG. 1B) by the rotating first and second blades 13 and 14, and is discharged from the opening 2A of the mixer drum 2. .

  The mixer drum 2 is rotationally driven using a traveling engine 3 mounted on the mixer vehicle 100 as a power source. The drive device 4 is driven by the rotation of the engine 3 and drives the mixer drum 2 to rotate by the fluid pressure of the working fluid.

  The rotational movement of the crankshaft in the engine 3 includes a power take-off mechanism 9 (PTO: Power take-off) for constantly taking out power from the engine 3, and a drive shaft 8 that connects the power take-out mechanism 9 and the drive unit 4 (see FIG. 2).

  As shown in FIG. 2, the power take-out mechanism 9 is provided with a rotation sensor 9 a that detects the rotation speed of the engine 3 and outputs a rotation speed signal corresponding to the detected rotation speed to the controller 10. It is good also as a structure which detects the rotational speed of the drive shaft 8 using the rotation sensor 9a.

  In the drive device 4, hydraulic oil is used as the working fluid. In addition, other incompressible fluids may be used as the working fluid instead of the working oil. The driving device 4 includes a hydraulic pump 5 as a fluid pressure pump that is driven by the engine 3 and discharges a working fluid, and a hydraulic motor 6 as a fluid pressure motor that is driven by the hydraulic pump 5 to rotationally drive the mixer drum 2. Prepare. The drive device 4 can forward / reverse and increase / decrease the mixer drum 2.

  The hydraulic pump 5 is rotationally driven by the power that is always taken out from the engine 3 via the power take-out mechanism 9. Therefore, the rotational speed of the hydraulic pump 5 is greatly affected by a change in the rotational speed of the engine 3 accompanying the traveling state of the vehicle. Therefore, in the mixer vehicle 100, the rotation speed of the hydraulic motor 6 is controlled by the controller 10 so that the mixer drum 2 is in the target rotation state according to the rotation speed of the engine 3.

  The hydraulic pump 5 is a swash plate type axial piston pump having a variable capacity. The hydraulic pump 5 receives a control signal from the controller 10 and switches the tilt angle of a swash plate (not shown) between the normal rotation direction and the reverse rotation direction. The hydraulic pump 5 includes a solenoid valve (not shown) for adjusting the tilt angle. The hydraulic pump 5 has its discharge direction and discharge capacity adjusted by switching the electromagnetic valve.

  The hydraulic oil discharged from the hydraulic pump 5 is supplied to the hydraulic motor 6, and the hydraulic motor 6 rotates. The rotation of the hydraulic motor 6 is transmitted to the mixer drum 2 via the speed reducer 7.

  As shown in FIG. 2, the hydraulic pump 5 is provided with a pressure sensor 5a as a pressure detector for detecting the pressure of the discharged hydraulic oil. The pressure sensor 5 a outputs a load pressure signal corresponding to the detected hydraulic oil pressure to the controller 10. Note that the pressure sensor 5 a may be provided not in the hydraulic pump 5 but in the hydraulic motor 6 to detect the pressure of the hydraulic oil in the hydraulic motor 6. As described above, the pressure sensor 5 a detects the pressure of the hydraulic oil in the driving device 4.

  The hydraulic motor 6 is a swash plate type axial piston motor having a variable capacity. The hydraulic motor 6 is rotationally driven in response to the supply of hydraulic oil discharged from the hydraulic pump 5. The hydraulic motor 6 includes an electromagnetic valve (not shown) that receives a second speed switching signal from the controller 10 and adjusts the tilt angle of a swash plate (not shown). The capacity of the hydraulic motor 6 can be switched in two stages, a small capacity for high speed rotation and a large capacity for normal rotation, by switching the electromagnetic valve. The hydraulic motor 6 is provided with a rotation sensor 6a (see FIG. 2) as a rotation speed detector that detects the rotation speed V of its output shaft (not shown).

  The controller 10 controls the driving device 4 and includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), I / O interface (input / output interface), and the like. It consists of a microcomputer. The RAM stores data in the processing of the CPU, the ROM stores in advance a control program of the CPU, and the I / O interface is used for input / output of information with a connected device. Control of the driving device 4 is realized by operating the CPU, RAM, and the like according to a program stored in the ROM.

  As shown in FIG. 2, when the engine 3 is started by the driver operating an ignition switch (not shown) in the cab 11, an ignition power source is input to the controller 10. As a result, the power relay 21 is switched, the main power from the main battery 23 is supplied to the controller 10, and the controller 10 is driven.

  A parking brake 31 and an operating device 32 for operating the mixer drum 2 are disposed in the cab 11.

  The parking brake 31 is provided with a detector that detects the lever position of the parking brake 31. When the parking brake 31 is applied, a stop signal is output from the detector to the controller 10.

  The operation device 32 includes a knob-type operation switch 32 a for switching the rotation direction and rotation speed of the mixer drum 2, a stop switch 32 b for emergency stop of the rotation of the mixer drum 2, and the mixer drum 2 is automatically rotated by stirring. And an automatic stirring switch 32c for the purpose.

  A command signal is output from the operating device 32 to the controller 10 based on the operation of the operation switches 32 a to 32 d by the driver. Based on the command signal, the controller 10 determines the target rotation state of the mixer drum 2, specifically, the rotation direction and the rotation speed.

  Here, the rotation operation of the mixer drum 2 will be described. When the automatic stirring switch 32c is on and there is no stop signal from the parking brake 31 and the vehicle speed is equal to or higher than a predetermined speed, the controller 10 determines that the vehicle is traveling. As a result, the controller 10 automatically rotates the mixer drum 2 while stirring to prevent the ready-mixed concrete from being discharged and to maintain the quality of the ready-mixed concrete.

  On the other hand, when the automatic agitation switch 32c is off, the controller 10 can reversely rotate the mixer drum 2 by operating the operation device 32 even when the vehicle is traveling. As a result, for example, when supplying the raw material to the elongated groove, the raw material in the mixer drum 2 can be discharged to the outside while the vehicle is traveling at an extremely low speed. Further, even when a stop signal is output from the parking brake 31, the controller 10 operates the operating device 32 to reversely rotate the mixer drum 2 so that the ready-mixed concrete in the mixer drum 2 can be discharged to the outside. Make it possible.

  A rear operation device 38 for enabling the operation of the mixer drum 2 outside the mixer vehicle 100 is disposed at the rear of the mixer vehicle 100. As with the operation device 32, the rear operation device 38 includes a knob-type operation switch 38 a for switching the rotation direction and rotation speed of the mixer drum 2 and a stop switch 38 b for emergency stop of the rotation of the mixer drum 2. Provided. Based on the driver operating the rear operation device 38, a command signal is output from the rear operation device 38 to the controller 10.

  The controller 10 controls the operation of the hydraulic pump 5 and the hydraulic motor 6 so that the rotation direction and rotation speed of the mixer drum 2 are in the target rotation state according to the calculated rotation speed of the engine 3. Specifically, the controller 10 calculates the discharge direction and discharge capacity of the hydraulic pump 5 and calculates the capacity of the hydraulic motor 6 so that the rotation direction and rotation speed of the mixer drum 2 are in the target rotation state. The control signal is output to the hydraulic pump 5 and the second speed switching signal is output to the hydraulic motor 6.

  A load pressure signal is input to the controller 10 from the hydraulic pump 5 through the pressure sensor 5a, and a rotation direction signal and a rotation speed signal are input from the hydraulic motor 6 through the rotation sensor 6a. The controller 10 controls the operations of the hydraulic pump 5 and the hydraulic motor 6 based on these input signals.

  Further, the mixer truck 100 is provided with an automatic cleaning / kneading operation device 39 for enabling automatic cleaning of the inside of the mixer drum 2 and mixing operation of ready-mixed concrete outside the mixer truck 100.

  By the way, in the conventional mixer truck, there was a problem that the discharge amount of the ready-mixed concrete pushed out by the rotating blades periodically increases and decreases during the discharge operation of discharging the ready-mixed concrete from the opening of the mixer drum. FIG. 3A is a characteristic diagram showing the relationship between the rotation angle of the mixer drum and the discharge amount of ready-mixed concrete during a discharge operation in which the mixer drum is driven at a substantially constant rotation speed as a comparative example. In a mixer drum provided with two blades, there are two peaks in which the amount of ready-mixed concrete increases during one revolution of the mixer drum.

  As a countermeasure, the controller 10 lowers the target rotational speed of the mixer drum 2 every time the first and second blades 13 and 14 come to a predetermined rotational position (rotational angle) during the discharging operation of the mixer drum 2, Control is performed to prevent the concrete discharge amount (flow rate) from periodically increasing and decreasing. Specifically, it is as follows.

  The controller 10 determines whether the first and second blades 13 and 14 have reached a predetermined position, and the mixer drum 2 based on the determination result of the rotational position determination unit 10A when the mixer drum 2 is discharged. A rotational speed control unit 10B that periodically corrects the target rotational speed to be low.

  The mixer vehicle 100 includes a rotation switch 12 that outputs a signal according to the rotation position of the mixer drum 2. The rotary switch 12 detects the magnetic force of the first and second magnets 33 and 34 attached to the outer periphery of the mixer drum 2, and the first and second magnets 33 and 34 pass through the rotary switch 12. Outputs rotation position signal.

  The first and second magnets 33 and 34 are arranged with a phase difference of 180 degrees with respect to the rotation center axis O so as to correspond to the positions of the first and second blades 13 and 14.

  The rotation switch 12 is not limited to the above-described configuration, and a limit switch that is turned on and off by contacting a protrusion attached to the outer periphery of the mixer drum 2 may be used.

  10 A of rotation position determination parts receive the detection signal of the rotational speed 12 of the hydraulic motor 6 by the rotation sensor 6a while receiving the detection signal of the rotation switch 12. FIG. The rotational position determination unit 10A is opened from the opening 2A by the first and second blades 13 and 14 when the mixer drum 2 is discharged according to the rotational position and rotational speed of the mixer drum 2 based on the detection signals of the rotation switch 12 and the rotation sensor 6a. It is determined that the mixer drum 2 has arrived at the rotational position before the amount of discharged ready-mixed concrete increases, and a trigger signal is output at a timing before the amount of ready-mixed concrete increases according to the rotational speed V of the hydraulic motor 6. .

  The rotational position determination unit 10A increases the timing at which the trigger signal is output after receiving the detection signal of the rotation switch 12 in accordance with the operation delay time of the drive device 4 as the rotational speed V of the hydraulic motor 6 increases. Composed.

  The method for detecting the rotational speed V of the hydraulic motor 6 is not limited to the configuration for receiving the signal of the rotation sensor 6a described above, but the configuration for receiving the signals of the operation switches 32a and 38a for switching the target rotational speed of the mixer drum 2. Also good.

  The rotational speed control unit 10B receives the trigger signal from the rotational position determination unit 10A, corrects the target rotational speed of the mixer drum 2 to be lower than the normal rotational speed, and makes the discharge amount of the ready-mixed concrete constant. Calculate the discharge capacity.

  The controller 10 outputs a control signal for controlling the operation of the hydraulic pump 5 so that the discharge capacity of the hydraulic pump 5 calculated by the rotation speed control unit 10B can be obtained.

  FIG. 3B is a timing chart showing the relationship between the rotational position signal, the trigger signal, the target rotational speed of the mixer drum 2, and the amount of ready-mixed concrete discharged with respect to the rotational angle of the mixer drum 2. During the discharging operation of the mixer drum 2, while the mixer drum 2 makes one rotation, the rotation position signal and the trigger signal rise twice, and the rotation speed of the mixer drum 2 decreases to twice. By controlling the rotational speed of the mixer drum 2 to periodically decrease at a timing corresponding to the rotational position of the first and second blades 13 and 14, the amount of ready-mixed concrete discharged is prevented from periodically fluctuating. It is done.

  In the rotational position determination unit 10A, as the rotational speed V of the hydraulic motor 6 increases, the rotational speed V of the hydraulic motor 6 changes by increasing the timing at which the trigger signal is output after receiving the detection signal of the rotational switch 12. Even so, the rotation of the mixer drum 2 is decelerated at the rotational position where the amount of ready-mixed concrete is to increase. Thereby, it can suppress that the discharge amount of the ready-mixed concrete extruded from 2 A of opening parts by the 1st, 2nd blades 13 and 14 fluctuates periodically.

  According to the above embodiment, the mixer vehicle 100 includes the drive device 4 that rotationally drives the mixer drum 2 and the controller 10 that controls the rotational speed of the mixer drum 2. Then, the controller 10 determines the rotational speed of the mixer drum 2 from the normal rotational speed based on the rotational position determination unit 10A that determines that the blades 13 and 14 have reached the predetermined rotational position and the determination result of the rotational position determination unit 10A. A rotation speed control unit 10B for lowering.

  In the mixer vehicle 100, when the ready concrete is discharged from the mixer drum 2, the controller 10 periodically controls the rotational speed of the mixer drum 2 to be low according to the rotational position of the blades 13, 14. The amount of ready-mixed concrete that is pushed out by 14 can be prevented from periodically increasing or decreasing. As a result, the ready-mixed concrete at a substantially constant flow rate is discharged from the mixer drum 2. For example, when the ready-mixed concrete discharged from the opening 2 </ b> A of the mixer drum 2 is put into a container such as a bucket, the amount of ready-mixed concrete varies. Can be suppressed.

  In the first embodiment, a rotary switch 12 that outputs a signal according to the rotational position of the mixer drum 2 is provided in the mixer truck 100. Then, the rotational position determination unit 10A determines that the blades 13 and 14 have come to a predetermined position based on a signal from the rotation switch 12.

  Thus, the rotational position determination unit 10A can accurately determine that the blades 13 and 14 have reached the predetermined rotational position based on the signal from the rotation switch 12, and the controller 10 can accurately determine the amount of ready-mixed concrete discharged. Well controlled.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. Below, it demonstrates centering on a different point from the said 1st Embodiment, the same code | symbol is attached | subjected to the structure same as the mixer vehicle of the said 1st Embodiment, and description is abbreviate | omitted.

  In the mixer vehicle according to the first embodiment, the rotary switch 12 that outputs a signal according to the rotational position of the mixer drum 2 is used. However, in the mixer vehicle according to the second embodiment, the same control is performed using the pressure sensor 5a. Is executed.

  The pressure sensor 5 a outputs a load pressure signal corresponding to the discharge pressure P of the hydraulic pump 5 to the controller 10. The discharge pressure P of the hydraulic pump 5 increases before the mixer drum 2 reaches the rotational position where the amount of raw concrete discharged pushed out by the first and second blades 13 and 14 increases.

  The rotational position determination unit 10C receives the detection signal of the pressure sensor 5a, determines that the detected discharge pressure P has risen above a preset threshold value, and outputs a trigger signal. Thereby, a trigger signal is output at a timing before the discharge amount of the ready-mixed concrete pushed out from the opening 2A by the first and second blades 13 and 14 increases. Further, the rotational position determination unit 10C may determine that the detected increase rate of the discharge pressure P is higher than a preset threshold value and output a trigger signal.

  The rotation speed control unit 10B receives the trigger signal from the rotation position determination unit 10C, and lowers the rotation speed of the mixer drum 2 from the normal rotation speed so that the discharge amount of the ready-mixed concrete is constant. Is calculated.

  The controller 10 outputs a control signal to the hydraulic pump 5 so that the discharge capacity of the hydraulic pump 5 calculated by the rotation speed control unit 10B can be obtained.

  As a result, in the mixer vehicle 100, the rotational speed of the mixer drum 2 decreases at a timing corresponding to the rotational position of the first and second blades 13 and 14 during the discharging operation of the mixer drum 2, and the first and second blades 13 and 14 Periodic fluctuations in the amount of fresh concrete extruded from the opening 2A can be suppressed.

  According to the second embodiment described above, the mixer vehicle 100 is provided with the pressure sensor (fluid pressure detector) 5 a that detects the discharge pressure P of the hydraulic pump 5 that drives the hydraulic motor 6. Then, the rotational position determination unit 10C determines that the blades 13 and 14 have reached a predetermined position based on a signal from the pressure sensor 5a. Thus, the rotational position determination unit 10C accurately determines the rotational position of the mixer drum 2 where the amount of ready-mixed concrete increases by using the characteristic that the discharge pressure P for driving the hydraulic motor 6 increases or decreases according to the rotational position of the mixer drum 2. Can be determined.

  The embodiment of the present invention has been described above. However, the above embodiment only shows a part of application examples of the present invention, and the technical scope of the present invention is limited to the specific configuration of the above embodiment. Absent.

  In the above embodiment, the blades 13 and 14 are determined to have reached the predetermined rotational position based on the signal from the rotary switch 12 or the pressure sensor 5a. Not only this but the rotation angle detector which detects the absolute rotation angle of the mixer drum 2 may be provided, and control which makes the rotation speed of the mixer drum 2 periodically low based on the signal of a rotation angle detector may be performed.

2 Mixer drum 4 Drive unit 5 Hydraulic pump (fluid pressure pump)
5a Pressure sensor (fluid pressure detector)
6 Hydraulic motor (fluid pressure motor)
DESCRIPTION OF SYMBOLS 10 Controller 10A, 10C Rotation position determination part 10B Rotation speed control part 12 Rotation switch 13, 14 Blade 100 Mixer vehicle

Claims (3)

In a mixer truck comprising a mixer drum capable of mounting ready-mixed concrete and having a blade for extruding ready-mixed concrete inside the mixer drum,
A driving device for rotationally driving the mixer drum;
A controller for controlling the rotational speed of the mixer drum,
The controller is
A rotational position determination unit that determines that the blade has reached a predetermined rotational position;
A mixer vehicle comprising: a rotation speed control unit configured to lower a rotation speed of the mixer drum from a normal rotation speed based on a determination result of the rotation position determination unit. A rotation switch that outputs a signal according to the rotation position of the mixer drum;
The mixer vehicle according to claim 1, wherein the rotational position determination unit determines that the blade has reached a predetermined position based on a signal from the rotation switch. The driving device includes:
A fluid pressure pump for discharging the working fluid;
A fluid pressure motor driven by the working fluid discharged by the fluid pressure pump to rotate the mixer drum;
A fluid pressure detector for detecting a fluid pressure for driving the fluid pressure motor,
2. The mixer vehicle according to claim 1, wherein the rotational position determination unit determines that the blade has reached a predetermined position based on a signal from the fluid pressure detector.

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