Concrete mixer truck

Abstract

A concrete mixer truck 100 includes a mixer drum 10 rotatably mounted on a vehicle, a drive motor 21 for rotationally driving the mixer drum 10, and a reducer 22 that reduces the speed of input rotation from the drive motor 21 and outputs the result to the mixer drum 10. The concrete mixer truck 100 comprises: an emergency motor 61 connected to an input gear 22a of the reducer 22 from the side opposite in the axial direction from the side to which the drive motor 21 is connected; and an electromagnetic clutch 62 that is provided between the emergency motor 61 and the reducer 22 and disconnects the transmission of power between the emergency motor 61 and the reducer 22.

Description

Mixer truck

[0001] The present invention relates to a mixer vehicle.

[0002] JP2016-68532A discloses a mixer vehicle in which a tool is connected to an emergency input section at the tip of the input shaft of the reducer and operated to rotate the mixer drum via the reducer.

[0003] In an emergency when the mixer drum loses power from the drive source due to an abnormality or the like, the mixer drum cannot be rotated in the direction of discharge of the fresh concrete to discharge the fresh concrete, which causes the fresh concrete inside the mixer drum to harden. Although the technology of Patent Document 1 allows the mixer drum to rotate in an emergency, because it is structured to connect a tool, the need to connect a tool makes it time-consuming and labor-intensive to discharge the fresh concrete inside the mixer drum, which may cause the fresh concrete inside the mixer drum to harden.

[0004] The present invention has been made in view of such problems, and has as its object to enable the rapid discharge of ready-mixed concrete in an emergency.

[0005] According to one aspect of the present invention, there is provided a mixer vehicle having a mixer drum rotatably mounted on a vehicle, a drive source that drives the mixer drum to rotate, and a reducer that reduces the input rotation from the drive source and outputs it to the mixer drum, and further comprising: a motor that is connected to the input rotating member of the reducer from the axially opposite side to the side to which the drive source is connected; and a clutch that is provided between the motor and the reducer and that disconnects the power transmission between the motor and the reducer.

[0006] Fig. 1 is a plan view of a mixer vehicle according to an embodiment of the present invention as seen from the side, and Fig. 2 is a configuration diagram showing a main part of the mixer vehicle according to an embodiment of the present invention.

[0007] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0008] First, the overall configuration of a mixer truck 100 according to an embodiment of the present invention will be described with reference to Figures 1 and 2. The mixer truck 100 is a vehicle that transports so-called ready-mixed concrete (hereinafter referred to as "ready-mixed concrete"), such as mortar or ready-mixed concrete, and is driven by the power of an engine (not shown). The driving source for driving the vehicle may be, for example, a driving motor, or an engine and a driving motor. The following description will be given of the case where the mixer truck 100 is loaded with ready-mixed concrete.

[0009] As shown in FIG. 1, the mixer truck 100 includes a cab 1, a base 2 extending in the longitudinal direction of the vehicle, a mixer drum 10 rotatably mounted on the base 2, a drum drive unit 20 that drives the mixer drum 10 to rotate, a hopper 30 that guides ready-mixed concrete fed from outside into the mixer drum 10, and a chute 40 that guides ready-mixed concrete discharged from the mixer drum 10 to a predetermined position.

[0010] The mixer drum 10 is a cylindrical container that rotates about a rotation axis C1. An opening 10a, through which ready-mixed concrete is charged and discharged, is provided at the rear end of the mixer drum 10 on the rear side of the vehicle, and a drive shaft 11 that extends outward along the rotation axis C1 is provided at the front end of the mixer drum 10 on the front side of the vehicle. The mixer drum 10 is supported by the frame 2 with the rear end, where the opening 10a is provided, raised higher than the front end.

[0011] The drive shaft 11 of the mixer drum 10 is connected to a drum drive device 20. As shown in FIG. 2 , the drum drive device 20 includes a drive motor 21 that is a drive source for the mixer drum 10, and a reducer 22 that reduces the input rotation from the drive motor 21 and outputs it to the mixer drum 10. The drive shaft 11 of the mixer drum 10 is connected to the drive motor 21 via the reducer 22. The drive motor 21 is an electric motor that can rotate forward and backward. Therefore, the mixer drum 10 is rotationally driven in the forward or reverse direction by the drive motor 21. The drive source for the mixer drum 10 may be a hydraulic motor.

[0012] 1 , a pair of blades 12, 13 are spirally arranged along the inner wall surface of the mixer drum 10 within the mixer drum 10. Each blade 12, 13 is divided into a front blade 12a, 13a arranged on the front side of the vehicle and a rear blade 12b, 13b arranged on the rear side of the vehicle at approximately the middle portion of the mixer drum 10. Each rear blade 12b, 13b is joined to the inner wall surface of the mixer drum 10 at the opening 10a and is joined to a cylindrical seal pipe 14 arranged on the rotation axis C1 of the mixer drum 10. The seal pipe 14 is provided to smoothly guide the ready-mixed concrete charged into the hopper 30 into the interior of the mixer drum 10.

[0013] The hopper 30 is disposed above the opening 10a of the mixer drum 10 to guide the ready-mixed concrete introduced from above the mixer truck 100 into the mixer drum 10 through the seal pipe 14. A hopper cover 31 that covers the opening of the hopper 30 is provided on the top of the hopper 30 so as to be rotatable via a hinge 31a. Meanwhile, a chute 40 is disposed below the opening 10a of the mixer drum 10 to guide the ready-mixed concrete discharged from the mixer drum 10 to a predetermined position.

[0014] The mixer truck 100 has three operating states of the mixer drum 10: a stirring state in which the mixer drum 10 is rotated at a first rotational speed to stir the ready-mixed concrete inside the mixer drum 10, a kneading state in which the mixer drum 10 is rotated at a second rotational speed faster than the first rotational speed to knead the ready-mixed concrete inside the mixer drum 10, and a discharge state in which the mixer drum 10 is rotated in the opposite direction to the stirring and kneading states to discharge the ready-mixed concrete from the opening 10a.

[0015] In the mixing state, the mixer drum 10 is driven to rotate in the forward direction, which is counterclockwise when viewed from the rear of the vehicle. In the mixing state, the blades 12, 13 rotate forward together with the mixer drum 10, so that the ready-mixed concrete in the mixer drum 10 moves toward the front of the mixer drum 10 while being mixed. By rotating the mixer drum 10 in this way to mix the ready-mixed concrete, separation or solidification of the ready-mixed concrete is suppressed.

[0016] In the mixing state, the mixer drum 10 is driven to rotate in the forward rotation direction at a second rotation speed that is faster than the first rotation speed of the mixer drum 10 in the mixing state. The mixing state is performed to mix the ready-mixed concrete before discharging it.

[0017] In the discharge state, the mixer drum 10 is driven to rotate in the reverse direction, that is, clockwise when viewed from the rear of the vehicle. In the discharge state, the blades 12, 13 rotate together with the mixer drum 10, so that the ready-mixed concrete moves to the rear of the mixer drum 10 while being agitated. By rotating the mixer drum 10 in the reverse direction in this way, the ready-mixed concrete can be discharged from the opening 10a of the mixer drum 10. The ready-mixed concrete discharged from the opening 10a of the mixer drum 10 is guided to a predetermined position via the chute 40.

[0018] 2 , the drum drive device 20 further includes a high-voltage battery 23 used to supply power to the drive motor 21, and an inverter 24 that converts direct current supplied from the high-voltage battery 23 into three-phase alternating current and supplies the three-phase alternating current to the drive motor 21. The high-voltage battery 23 has an output voltage of, for example, DC 300 V. The inverter 24 generates three-phase alternating current based on commands from the controller 50, and the drive motor 21 is controlled by the three-phase alternating current generated by the inverter 24.

[0019] The inverter 24 includes a switching circuit 24a that performs switching operations using switching elements, a detection unit 24b that detects the output current and applied voltage of each phase of the inverter 24, and a fail-safe circuit 24c that protects the inverter 24 in the event of an abnormality. The switching elements of the switching circuit 24a are semiconductor switching elements such as IGBTs and MOSFETs, and generate three-phase AC current by performing switching operations based on commands from the controller 50. The detection unit 24b is used to detect abnormalities such as disconnections and short-circuited or stuck-open switching of the switching elements. The fail-safe circuit 24c shorts the coil of the drive motor 21 by operating the switching elements in the event of an abnormality, for example. The detection unit 24b may detect the input current of the inverter 24, or may perform status detection to detect other abnormalities that would prevent the mixer drum 10 from being driven by the power of the drive motor 21, such as an abnormality that requires activation of the fail-safe circuit 24c.

[0020] The controller 50 is a control device for the mixer drum 10 and is composed of a microcomputer equipped with a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), an I / O interface (Input / Output Interface), etc. The RAM stores data for CPU processing, the ROM stores the CPU's control programs and the like in advance, and the I / O interface is used for inputting and outputting information to and from connected devices. By operating the CPU, RAM, etc. in accordance with the programs stored in the ROM, the operation of the drum drive device 20, that is, the operation of the drive motor 21 through the operation of the inverter 24, is controlled, thereby controlling the mixer drum 10.

[0021] The controller 50 is programmed to be able to execute at least the processes necessary to execute the control according to this embodiment. The controller 50 may be composed of multiple microcomputers. The controller 50 may be configured as a single device, or may be divided into multiple devices and configured to perform distributed processing of the control according to this embodiment among the multiple devices.

[0022] The detection unit 24b is electrically connected to the controller 50, and various detection values ​​detected by the detection unit 24b are input to the controller 50. The inverter 24 is also connected to the controller 50, and a command value for operating the inverter 24 is output from the controller 50.

[0023] An ignition switch (IGSW) 81 is further electrically connected to the controller 50, and the on / off of the power supply that supplies power to the controller 50 is switched by the IGSW 81. The IGSW 81 is electrically connected to a low-voltage battery 70, which will be described later, and based on the low-voltage battery 70, an accessory (ACC) power supply and an IG power supply are configured as power supplies that can be turned on / off by the IGSW 81. The ACC power supply mainly supplies power to electrical components and small electrical devices that consume little power, and the IG power supply mainly supplies power to electrical devices that consume a large amount of power.

[0024] The IGSW 81 has an ACC position for turning on the ACC power supply and an IG position for turning on the IG power supply. Therefore, when the IGSW 81 is switched to the ACC position, the ACC power supply is turned on, and when the IGSW 81 is switched to the IG position, the IG power supply is turned on. The ACC power supply is not the IG power supply (it is different from the IG power supply), but it is also turned on in the IG position. The IGSW 81 may be a rotary type or a push-button type. If the drive source for the mixer vehicle 100 is a travel motor, that is, if the mixer vehicle 100 is an EV, a switch that turns on / off multiple power supplies that can be turned on / off, similar to the IGSW 81, can be used instead of the IGSW 81.

[0025] The controller 50 is powered by the ACC power supply when in the ACC position, and by the IG power supply when in the IG position. When in the ACC position, the electrical system of the ACC power supply, indicated by the thin solid line, is enabled (ACC on), and when in the IG position, the electrical system of the IG power supply, indicated by the thin dashed line, is enabled (IG on).

[0026] The switching circuit 24a of the inverter 24 is electrically connected to the controller 50 using the electrical system of the IG power supply. In other words, the switching circuit 24a is configured as part of the electrical system of the IG power supply. Therefore, the inverter 24 is operable when the IG position is selected, but is inoperable when the IG SW 81 is switched from the IG position to the ACC position or to a position other than the IG position (IG OFF). Therefore, when the IG is OFF, the mixer drum 10 cannot be driven by the power of the drive motor 21. In the following, the IG OFF case will be described as the ACC ON case.

[0027] When the ignition is off, the drive motor 21 is in a state where the rotating shaft 21a can rotate freely by itself. Even when the drive source of the mixer drum 10 is a hydraulic motor, the solenoid valves of the hydraulic circuit that control the hydraulic motor are not energized when the ignition is off. As a result, the rotating shaft of the hydraulic motor is in a state where it can rotate to the extent that the mixer drum 10 can rotate, for example, when unevenness of the ready-mixed concrete inside the mixer drum 10 is being corrected or when chipping work is being performed.

[0028] An emergency stop switch 82 is also electrically connected to the controller 50. The emergency stop switch 82 is connected to the electrical system of the IG power supply of the controller 50, and when the emergency stop switch 82 is turned on (emergency stop operation), the electrical system of the IG power supply of the controller 50 is cut off and becomes non-energized. Therefore, even in the event of an emergency stop, the mixer drum 10 cannot be driven by the power of the drive motor 21. The controller 50, together with the drum drive device 20, constitutes a control system 90 for the mixer drum 10. The control system 90 further includes an IG switch 81 and the emergency stop switch 82.

[0029] In an emergency situation where the mixer truck 100 loses power from the drive motor 21 due to an abnormality or the like, the drive motor 21 cannot rotate the mixer drum 10 in the reverse direction (the direction in which the ready-mixed concrete is discharged) to quickly discharge the ready-mixed concrete, which causes the ready-mixed concrete in the mixer drum 10 to solidify. For this reason, the mixer truck 100 is configured as will be further explained below.

[0030] 1 and 2, the mixer truck 100 further includes an emergency drive device 60. Fig. 2 is a configuration diagram showing the mixer drum 10, the drive motor 21, the reducer 22, and the emergency drive device 60 as viewed from above. The emergency drive device 60 further includes an emergency motor 61 that is connected to the mixer drum 10 via the reducer 22 separately from the drive motor 21, and an electromagnetic clutch 62 that is provided between the emergency motor 61 and the reducer 22, i.e., in a power transmission path that connects the emergency motor 61 and the reducer 22.

[0031] The emergency motor 61 is an electric motor, and is connected to an input gear 22a, which is an input rotating member of the reducer 22, from the axially opposite side to the side to which the drive motor 21 is connected. The input rotating member may be the input shaft of the reducer 22. The electromagnetic clutch 62 connects and disconnects the power transmission between the emergency motor 61 and the reducer 22. The electromagnetic clutch 62 is disengaged when energized to interrupt the power transmission between the emergency motor 61 and the reducer 22, and is engaged when deenergized to connect the emergency motor 61 and the reducer 22. In other words, the electromagnetic clutch 62 is a normally closed type clutch that is engaged and disengaged depending on whether or not it is energized.

[0032] The electromagnetic clutch 62, which is engaged when de-energized, can be engaged by turning the IG SW 81 off in an emergency when the drive motor 21 loses power. Therefore, the mixer drum 10 can be rotated in the reverse direction by the emergency motor 61 via the electromagnetic clutch 62, allowing for rapid discharge of ready-mixed concrete. Furthermore, since the reducer 22 for driving the mixer drum 10 can be used as is, no additional mechanism for deceleration is required, simplifying the emergency configuration. Furthermore, since the minimum rotation speed (e.g., 1 to 2 rpm) required to discharge ready-mixed concrete from the mixer drum 10 in an emergency is sufficient, the reduction ratio of the reducer 22 can be used to make the emergency motor 61 as small as possible.

[0033] An electric clutch that is driven by an electric actuator and is released when energized and engaged when de-energized may be used instead of the electromagnetic clutch 62. In this case, as in the case where the electromagnetic clutch 62 is used, the ready-mixed concrete can be quickly discharged.

[0034] The emergency motor 61 is arranged to rotate about a common axis A1 with the drive motor 21 and the input gear 22a of the reducer 22. The common axis A1 is, for example, the rotation axis of the input gear 22a, and in this case, the rotation shaft 21a of the drive motor 21 and the rotation shaft 61a of the emergency motor 61 are aligned with the rotation axis of the input gear 22a, so that the drive motor 21, the emergency motor 61, and the input gear 22a are arranged coaxially, so to speak. As a result, the radial protrusion of the emergency motor 61 is suppressed, and compactness is achieved.

[0035] The input gear 22a of the reducer 22 meshes with the output gear 22b of the reducer 22. The number of teeth of the output gear 22b is set to be greater than the number of teeth of the input gear 22a, and the rotation of the input gear 22a is reduced by the output gear 22b. The drive shaft 11 of the mixer drum 10 is connected to the output gear 22b of the reducer 22 from the axially opposite side to the side to which the drive motor 21 is connected. Meanwhile, the rotation axes of the input gear 22a and the output gear 22b are radially spaced apart from each other, thereby creating extra space for installing an emergency drive device 60 that is connected to the input gear 22a from the same axial side as the mixer drum 10. The reducer 22 may have a structure in which an additional gear is interposed between the input gear 22a and the output gear 22b, or may have a structure including a planetary gear mechanism.

[0036] The mixer truck 100 is equipped with a low-voltage battery 70 in addition to the high-voltage battery 23. The low-voltage battery 70 has an output voltage of, for example, DC 24 V, and power is supplied from the low-voltage battery 70 to the emergency motor 61. A discharge rotation SW 83 for driving the emergency motor 61 is connected to the emergency motor 61. The discharge rotation SW 83 is an operation unit that can perform a discharge rotation operation to drive the emergency motor 61 in the reverse direction, and is provided, for example, on an operation panel outside the cab 1. This allows the discharge rotation SW 83 to be operated while checking the conditions around the mixer drum 10 and the rotation of the mixer drum 10. The discharge rotation SW 83 uses the electrical system of the ACC power supply.

[0037] The electromagnetic clutch 62 is electrically connected to the controller 50 of the control system 90 using the electrical system of the IG power supply and is controlled by the controller 50. The electromagnetic clutch 62 is disengaged in response to a rotation command for the mixer drum 10 under the control of the controller 50. The presence or absence of a rotation command for the mixer drum 10 can be determined based on internal processing of the controller 50, for example, by checking the on / off state of a drive flag that is turned on when the mixer drum 10 is driven. The presence or absence of a rotation command for the mixer drum 10 may also be determined based on a signal from the detection unit 24b of the inverter 24.

[0038] A clutch release command is input from the controller 50 to the electromagnetic clutch 62 in response to a rotation command for the mixer drum 10. As a result, the electromagnetic clutch 62 is energized by the controller 50 (and therefore energized by the control system 90) and released. Therefore, when the mixer drum 10 rotates normally in response to the rotation command, the electromagnetic clutch 62 disconnects the emergency motor 61 from the mixer drum 10. Therefore, the normal rotation of the mixer drum 10 is not hindered by the emergency motor 61.

[0039] When the rotation command for the mixer drum 10 is no longer issued, the controller 50 no longer issues a clutch release command to the electromagnetic clutch 62. As a result, the electromagnetic clutch 62 is not energized by the controller 50 (and therefore not energized by the control system 90) and is engaged. In other words, the electromagnetic clutch 62 is engaged or released depending on whether or not a control command from the controller 50 is issued, i.e., whether or not it is energized.

[0040] Based on a signal from the detector 24b of the inverter 24, the controller 50 detects an electrical failure in the control system 90 for the mixer drum 10 as an abnormality in the inverter 24. The electrical failure is an electrical failure that makes it impossible to drive the mixer drum 10 with the power of the drive motor 21, and is detected as such an electrical failure, for example, a broken wire in the inverter 24, or a switching element that is fixed short-circuited or fixed open. Electrical failures in the control system 90 also include a broken wire in the electrical system of the IG power supply, poor contact in the IG position of the IG SW 81, a malfunction of the controller 50, etc.

[0041] When the controller 50 detects an electrical failure, it activates the fail-safe circuit 24c of the inverter 24 to protect the inverter 24. When the fail-safe circuit 24c is activated, the inverter 24 circuit is also in a state where the drive motor 21 cannot be driven due to the activation of the inverter 24.

[0042] If the controller 50 detects an electrical failure, it also performs fail-safe control to prohibit a clutch release command to the electromagnetic clutch 62. As a result, the electromagnetic clutch 62 is not energized and is engaged. Therefore, the electromagnetic clutch 62 is not energized by the controller 50 and is engaged not only when the IG is off, but also in the event of an electrical failure in the control system 90. As a result, even if an electrical failure occurs in the control system 90 and it becomes impossible to drive the mixer drum 10 with the power of the drive motor 21, the ready-mixed concrete can be quickly discharged using the emergency motor 61.

[0043] As described above, when the emergency stop SW 82 is turned on, the controller 50 cuts off the electrical system of the IG power supply and puts it into a non-energized state. Therefore, the electromagnetic clutch 62 is not energized by the controller 50 and is engaged even during an emergency stop. This makes it possible to rotate the mixer drum 10 by the emergency motor 61 even during an emergency stop. Therefore, even though the drive motor 21 is prohibited from being driven during an emergency stop, the emergency motor 61 can be safely operated at the minimum rotation speed that allows the ready-mixed concrete to be discharged, thereby enabling the ready-mixed concrete to be discharged quickly during an emergency stop.

[0044] The emergency motor 61 is connected to the low-voltage battery 70 via a changeover switch 84. The changeover switch 84 is a switch that connects or disconnects the emergency motor 61 to or from the low-voltage battery 70 that supplies power to the emergency motor 61, and is switched as follows.

[0045] That is, the changeover SW 84 has a connection position and a short-circuit position, and the position is changed over between the connection position and the short-circuit position. Fig. 2 shows the changeover SW 84 in a state where it is changed over to the short-circuit position.

[0046] In the connected position, the positive wiring 61b of the emergency motor 61 is connected to the positive terminal 70a of the low-voltage battery 70, and the negative wiring 61c of the emergency motor 61 is connected to the negative terminal 70b of the low-voltage battery 70. As a result, the emergency motor 61 is connected to the low-voltage battery 70. In the short-circuit position, the positive wiring 61b and negative wiring 61c of the emergency motor 61 are connected. As a result, a closed circuit SC including the emergency motor 61 is formed, as shown in FIG. 2 .

[0047] The switch 84 forms a closed circuit SC, causing the emergency motor 61 to function as a brake. Therefore, in the short-circuit position, the emergency motor 61, functioning as a brake, brakes the rotation around the common axis A1, thereby braking the rotation of the mixer drum 10.

[0048] An operation circuit 85 of the selector SW 84 is electrically connected to the selector SW 84. An ACC power supply electrical system is used for the selector SW 84 and the operation circuit 85. As shown in Fig. 2, the discharge rotation SW 83 is electrically connected to the operation circuit 85, and when a discharge rotation operation is performed using the discharge rotation SW 83, the operation circuit 85 sets the selector SW 84 to the connection position and connects the emergency motor 61 and the low-voltage battery 70.

[0049] As a result, regardless of whether the electromagnetic clutch 62 is not energized during an electrical failure, an emergency stop, or the like (in other words, including when the electromagnetic clutch 62 is not energized), power is supplied from the low-voltage battery 70 to the emergency motor 61, thereby enabling the emergency motor 61 to be driven. In this case, the emergency motor 61 does not function as a brake, and therefore allows the mixer drum 10 to rotate without braking.

[0050] When the discharge rotation operation using the discharge rotation SW 83 is not being performed, the operating circuit 85 sets the changeover SW 84 to the short-circuit position to form a closed circuit SC. Therefore, when the discharge rotation operation is not being performed, the emergency motor 61 functions as a brake regardless of whether the electromagnetic clutch 62 is de-energized or not.

[0051] Even in this case, when the mixer drum 10 rotates normally in response to a rotation command, the electromagnetic clutch 62 is released in response to the rotation command for the mixer drum 10, so there is no interference with the rotation of the mixer drum 10. As a result, it is not necessary to switch the changeover SW 84 depending on whether the electromagnetic clutch 62 is de-energized in the event of an electrical failure or an emergency stop, etc., thereby simplifying the operating circuit 85. In addition, because the changeover SW 84 causes the emergency motor 61 to function as a brake, this is advantageous in terms of cost compared to using, for example, a motor with a brake instead of the emergency motor 61.

[0052] By making the emergency motor 61 function as a brake when the discharge rotation operation is not being performed, including when the electromagnetic clutch 62 is not energized in the event of an electrical failure or emergency stop, it is possible to prevent or suppress the mixer drum 10 from suddenly rotating (reverse rotating) due to unevenness of the ready-mixed concrete inside the mixer drum 10 immediately after the IG is turned off, an electrical failure occurs, or an emergency stop operation is performed. Furthermore, since the rotation of the mixer drum 10 can be prevented or suppressed even after the discharge rotation operation has been completed, safety is also ensured when performing work such as chipping to remove ready-mixed concrete that has solidified inside the mixer drum 10.

[0053] As described above, the emergency motor 61 is supplied with power from the low-voltage battery 70, and the ACC power supply electrical system is used for the discharge rotation SW 83, the changeover SW 84, and the operating circuit 85. Therefore, even when the mixer drum 10 cannot be driven by the power of the drive motor 21 due to an IG-off operation, an electrical failure in the control system 90, or an emergency stop operation, the emergency motor 61 can be driven by receiving power from the low-voltage battery 70.

[0054] The emergency motor 61 may further switch the switch 84 depending on whether an electrical failure or an emergency stop has occurred. This disables the discharge rotation operation when there is no emergency, thereby reducing unnecessary power consumption. In this case, the controller 50 may be configured to output a signal to the activation circuit 85 via the electrical system of the ACC power supply in the event of an electrical failure or an emergency stop, and the activation circuit 85 may be configured to switch the switch 84 depending on whether an electrical failure or an emergency stop has occurred based on the signal.

[0055] Instead of providing the operation circuit 85, the controller 50 may control the changeover SW 84. In this case, by electrically connecting the discharge rotation SW 83 and the changeover SW 84 to the controller 50 using the electrical system of the ACC power supply, the changeover SW 84 can be controlled depending on whether or not the discharge rotation operation is being performed, and the changeover SW 84 can be controlled by the controller 50 even when the IG is off, when there is an electrical failure, or when an emergency stop occurs.

[0056] The configuration, operation, and effects of the embodiment of the present invention will be described below.

[0057] The mixer truck 100 has a mixer drum 10 rotatably mounted on the vehicle, a drive motor 21 that drives the mixer drum 10 to rotate, and a reducer 22 that reduces the input rotation from the drive motor 21 and outputs it to the mixer drum 10.The mixer truck 100 is also equipped with an emergency motor 61 that is connected to an input gear 22a of the reducer 22 from the axially opposite side to the side to which the drive motor 21 is connected, and an electromagnetic clutch 62 that is provided between the emergency motor 61 and the reducer 22 and that disconnects the power transmission between the emergency motor 61 and the reducer 22.

[0058] With this configuration, in an emergency when the mixer drum 10 loses power from the drive motor 21, the emergency motor 61 can be connected to the reducer 22 by the electromagnetic clutch 62, allowing the emergency motor 61 to rotate the mixer drum 10 in the reverse direction, thereby enabling the ready-mixed concrete to be discharged quickly. Furthermore, since the reducer 22 used to drive the mixer drum 10 can be used as is, no new mechanism for deceleration is required, simplifying the emergency configuration. Furthermore, since it is sufficient to obtain the minimum rotation speed necessary to discharge the ready-mixed concrete from the mixer drum 10 in an emergency, the reduction ratio of the reducer 22 can be used to make the motor as small as possible.

[0059] The emergency motor 61 is arranged to rotate around the axis A1 common to the drive motor 21 and the input gear 22a of the reducer 22.

[0060] According to this configuration, the emergency motor 61 is arranged coaxially with the drive motor 21 and the input gear 22a of the reducer 22, so that the emergency motor 61 is prevented from protruding radially, which contributes to compactness.

[0061] The electromagnetic clutch 62 is electrically connected to a control system 90 for the mixer drum 10 and is disengaged by being energized by the control system 90 in response to a rotation command for the mixer drum 10 .

[0062] According to this configuration, when the mixer drum 10 rotates normally in response to a rotation command, the emergency motor 61 is separated from the mixer drum 10 by the electromagnetic clutch 62, so that the normal rotation of the mixer drum 10 is not hindered by the emergency motor 61.

[0063] The electromagnetic clutch 62 is electrically connected to the control system 90 of the mixer drum 10, and is engaged in the event of an electrical failure in the control system 90 that makes it impossible to drive the mixer drum 10 using power from the drive motor 21, or in the event of an emergency stop in which an emergency stop operation is performed on the control system 90.

[0064] According to this configuration, when an electrical failure in the control system 90 prevents the mixer drum 10 from being driven by the power of the drive motor 21, the electromagnetic clutch 62 is engaged, allowing the ready-mixed concrete to be quickly discharged using the emergency motor 61. Furthermore, even during an emergency stop, the mixer drum 10 can be rotated by the emergency motor 61, so even if the drive motor 21 is prohibited from being driven by an emergency stop, the emergency motor 61 can be safely operated at the minimum rotation speed that allows the ready-mixed concrete to be discharged, thereby allowing the ready-mixed concrete to be quickly discharged.

[0065] The mixer truck 100 further includes a discharge rotation SW 83, which is an operating unit capable of performing a discharge rotation operation that rotates the mixer drum 10 in the reverse direction using the emergency motor 61. When the discharge rotation operation is performed while the electromagnetic clutch 62 is engaged and not energized, the emergency motor 61 drives the mixer drum 10 to rotate in the reverse direction, and when the discharge rotation operation is not performed while the electromagnetic clutch 62 is not energized, the emergency motor 61 functions as a brake that stops the rotation of the mixer drum 10.

[0066] According to this configuration, even when the electromagnetic clutch 62 is not energized in the event of an electrical failure or emergency stop, rotation of the mixer drum 10 can be prevented or suppressed until the discharge rotation operation is performed. Therefore, it is possible to prevent or suppress the mixer drum 10 from unexpectedly rotating (reverse rotating) due to unevenness of the ready-mixed concrete inside the mixer drum 10 immediately after the IG is turned off, immediately after an electrical failure occurs, or immediately after an emergency stop operation. In addition, because rotation of the mixer drum 10 can be prevented or suppressed even after the discharge rotation operation is completed, safety is ensured during work such as chipping work to remove ready-mixed concrete stuck inside the mixer drum 10.

[0067] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0068] This application claims priority based on Japanese Patent Application No. 2023-142384, filed with the Japan Patent Office on September 1, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A mixer vehicle comprising: a mixer drum rotatably mounted on a vehicle; a drive source for driving and rotating the mixer drum; and a reducer for reducing the input rotation from the drive source and outputting it to the mixer drum, a motor connected to an input rotating member of the reducer from the axially opposite side to the side to which the drive source is connected; and a clutch provided between the motor and the reducer for connecting and disconnecting power transmission between the motor and the reducer.

2. A mixer vehicle as claimed in claim 1, wherein the motor is arranged to rotate about a common axis with the drive source and the input rotating member of the reducer.

3. A mixer vehicle according to claim 1, wherein the clutch is electrically connected to a control system for the mixer drum and is released by energizing the clutch from the control system in response to a rotation command for the mixer drum.

4. A mixer truck as described in claim 1, wherein the clutch is electrically connected to a control system for the mixer drum, and is engaged in a state where it is not energized by the control system in the event of an electrical failure in the control system that causes the mixer drum to be unable to be driven by the power of the drive source, or in the event of an emergency stop in which an emergency stop operation is performed on the control system.

5. A mixer truck as described in claim 1, further comprising an operating unit capable of performing a discharge rotation operation to rotate the mixer drum in the direction of discharging fresh concrete using the motor, wherein the motor drives the mixer drum to rotate in the direction of discharging fresh concrete when the discharge rotation operation is performed when the clutch is engaged, and functions as a brake to brake the rotation of the mixer drum when the discharge rotation operation is not performed when the clutch is engaged.

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