JPH0212163B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a drive control device for a driven body such as a mixer drum mounted on a concrete mixer truck, and is designed to minimize discharge pulsation, especially when discharging fresh concrete from the mixer drum. This invention relates to a drive control device.

In general, a concrete mixer truck has a mixer drum rotatably mounted on the vehicle body, and is driven by power from the vehicle's engine via a drive device to rotate forward, stop, reverse, and increase/decelerate to load ready-mixed concrete. , adding stirring and kneading while running,
Work such as discharging is now being carried out at the pouring point. Two screw blades made of screw ribbons are installed with a phase difference of 180° on the inner wall of the mixer drum to perform the various operations mentioned above. A unique linked drive system and electrical control system are interposed between the two in order to match the engine speed and output related to the vehicle's running condition and the speed and power required for various operations on the mixer drum under that condition. has been done.

When discharging fresh concrete by reversing the mixer drum, pulsations occur in the discharge amount depending on the angular position of the screw blade. Conventionally, in order to limit this pulsation tendency, a small blade called a discharge blade b is inserted between the main blades a at the discharge rear end portion, as shown in the open view of the rear end of the mixer drum in FIG. fresh concrete
According to the results of the JIS A1101-1950 slump test method, this discharge blade is effective in preventing discharge pulsation in the case of high slump and soft materials.
If the fresh concrete has a high viscosity and low fluidity, on the contrary, it will create resistance and become clogged, impeding smooth discharge and causing adverse effects.

The present invention provides a control means that can minimize the pulsation of fresh concrete discharge without using a discharge blade. By equalizing the discharge speed in this way, the discharge speed can be improved, and as a result, it is possible to improve the efficiency of placing fresh concrete and the operating efficiency of the concrete mixer truck. To achieve this objective, the mixer drum drive control device for a mixer truck of the present invention is rotatably mounted on the vehicle body and connected to a drive device for forward and reverse rotation. A sensor is installed to detect the rotational angle phase of the mixer drum on a mixer drum in which two screw blades are installed with a rotational phase difference of 180 degrees, and the signal is used to rotate the drive device via the information processing device. The rotational speed of the mixer drum is set to a low speed during each 1/4 rotation phase of the reverse rotation of the mixer drum during phases when the amount of fresh concrete discharged by the screw blade increases, and during phases when the amount of fresh concrete discharged by the screw blade decreases. Made it switch to high speed.

Hereinafter, the present invention will be explained specifically and in detail with reference to embodiments shown in the accompanying drawings.

FIG. 2 shows a side view of a concrete mixer truck. A mixer drum 2 is rotatably mounted on the vehicle body 1, and is driven by a drive device 3 for forward rotation, stop, reverse rotation, speed increase, and deceleration. It's becoming like that. In this example, the drive device 3 is a power take-off device 5 called PTO from the engine 4 of the vehicle.
A hydraulic motor 7 is drivingly connected to the mixer drum 2 and rotates by receiving pressure oil from a reversible variable displacement pump 6 such as a swash plate pump that is rotationally driven through the mixer drum 2 .

As shown in FIG. 3, the reversible variable displacement pump 6 is linked to a control motor 11 operated via an information processing device 10 including a microcomputer, which is operated by an operating device 8 inside the vehicle interior or an operating device 9 outside the vehicle interior. The discharge direction and capacity of the pressure oil are controlled, thereby controlling the rotational direction and speed of the hydraulic motor 7 and thus the mixer drum.

In order to maintain the rotation of the mixer drum at the optimum rotation suitable for each operation, regardless of changes in the running/stopping state of the vehicle, a rotation speed signal from a rotation speed sensor 12 connected to the mixer drum 2 is input to the information processing device 10. However, the information processing device compares the rotation speed signal with a set rotation speed signal and performs rotation control. When the mixer drum 2 is reversed to discharge fresh concrete, the vehicle is stopped and the engine 4 is normally in an idle state with low revolutions and low output, so it is necessary to increase the speed and perform information processing. From the device 10 to the engine accelerator drive device 1
3, an increase/deceleration signal is output. Furthermore, for the purpose of the present invention to prevent pulsating discharge of fresh concrete from the mixer drum 2, a rotational phase sensor 14 is provided to detect the rotational angular position of the mixer drum 2, and a rotational phase signal is input to the information processing device 10. It's summery.

FIG. 4 shows a partially broken mixer drum 2 to show the internal structure related to the present invention. On the inner wall of the mixer drum 2, two helical ribbon-shaped screw blades 15A and 15B are arranged from the front to the rear.
They are planted with a phase difference of 180°. A cylindrical feed chute 17 used for loading fresh concrete material is disposed at the center of the rear opening 16 of the mixer drum 2. Supported. feed shoot 1
7 and the inner edges of the screw blades 15A, 15B.
8 is arranged, but the screw blade 15
The portion where the extension chute 18 does not exist between A, 15B and the feed chute 17 is opened and communicates with an annular discharge port 19 between the mixer drum 2 and the feed chute 17. By rotating the mixer drum 2 in the reverse direction, the mixed concrete inside is scraped up rearward and upward alternately by the screw blades 15A and 15B, and is discharged from the annular discharge port 19 through the opening.

Figure 5 A, B, C, and D indicate the arrow R of the mixer drum 2 when viewed from the rear opening 16 of the mixer drum 2.
In order during one rotation of the reverse rotation shown by
Screw blade 15 rotated 90° or 1/4
It shows the relationship between the angular phase positions of A and 15B and the amount of fresh concrete C that is being discharged at that position. In the rotation angle phases A and C of FIG. 5, the amount of fresh concrete pushed out from the discharge port 19 by the screw blades 15A and 15B is maximum, and the discharge amount is larger as shown by arrow D, but it is 1/4 In the rotational angle phases (b) and (d) where the rotation is shifted, the ready-mixed concrete carried by the screw blades 15B and 15A is being transferred to the discharge port 19, and the discharge amount is small or non-existent. Therefore, if the mixer drum reversely rotates at a constant speed, fresh concrete will be discharged in a pulsating manner.

In the present invention, the angular phase of each quarter rotation of the mixer drum 2 is detected by the rotational phase sensor 14 from a portion of the drive device 3 near the mixer drum 2, for example, and the rotational phase signal is input to the information processing device 10, In addition to the arithmetic processing in the information processing device 10, the rotation speed of the mixer drum 2 can be changed every 1/4 rotation. Then, the rotational speed is set to be high as shown by arrow R' during the rotational phase periods of FIG. The control device is configured so that the change between high-speed rotation and low-speed rotation for each 1/4 rotation phase of the mixer drum 2 based on the signal from the rotational phase sensor 14 occurs only when the mixer drum 2 rotates in reverse.

FIG. 6 shows an example of the rotational phase sensor 14, in which a cam 21 with a height range of 90° is mounted on a shaft 20 that rotates the same as the mixer drum 2, and a proximity sensor 22 is arranged opposite to this. It is a form. The rotational phase sensor 14 may have a mechanical structure or may have an electrically or magnetically actuated structure, and the signal detection location can be selected.

FIG. 7 shows a block diagram of the control operation of the mixer drum drive control device including the present invention. The rotation of the mixer drum 2 is measured by the rotational speed sensor 12 and the measured value is taken in 23 . Furthermore, the rotation speed setting 24 and switch operation 25 are performed by the operator's operation of the operating device 8 or 9, and the intake 26 and intake 2 are respectively performed.
After 7, work type identification 28 is performed. Furthermore, both the reverse discharge signal 29 and the rotational phase sensor 14 signal are captured 30 according to the present invention. These input signals are compared and discriminated in the comparator 31, and the accelerator amount of the engine 4 is calculated 32 and the discharge amount of the reversible variable displacement pump 6 is calculated 33. These are taken out as outputs 34 and 35, and the accelerator drive device 18 and is input to the pump actuator 36. 37 indicates a display section.

In addition, in the above examples, we have described the method applied to low slump, high viscosity fresh concrete, but it can also be applied to normal hardness (slump 5 to 10 cm) or high slump soft concrete. The phase of the screw blade is different from that in the above embodiment, and for fresh concrete of normal hardness, the rotation speed is set to high speed at the rotational phases of Figure 9 (b) and (d), and for fresh concrete with high slump, the rotation speed is set to high speed during the rotation phase period of Figure 8 (ro). The rotational speed is increased during the rotational phase of 2 and 2.

According to the present invention, when discharging fresh concrete from the mixer drum of a mixer truck, the rotation speed can be switched between high and low speeds with a 1/4 rotation phase, and the rotation phase period when a large amount of discharge is produced is changed to a low speed. By appropriating this amount, it is possible to make the rotational phase period with a small amount of emissions elapse at high speed and in a short time.

As a result, according to the present invention, it is possible to prevent or reduce the pulsating discharge of fresh concrete, thereby shortening the discharge time and improving the operating efficiency of the mixer truck. .

[Brief explanation of drawings]

Fig. 1 is a diagram showing the conventional blade arrangement on the rear end opening surface of the mixer drum, Fig. 2 is a diagram showing the side surface of the concrete mixer truck and the mixer drum drive device, Fig. 3 is a related line diagram of the control system, and Fig. 4 is a partially cutaway side view of the mixer drum, Figure 5A,
B, C, and D are diagrams sequentially showing the progress of the rotational phase as seen from the rear opening of the mixer drum, FIG. 6 is a diagram showing an example of a rotational phase sensor, and FIG. 7 is a control of the mixer drum drive control device of the present invention. The operation block diagrams in Figure 8 A, B, C, and D are diagrams showing the progression corresponding to the rotational phase of the mixer drum, similar to Figure 5, in the case of high slump soft fresh concrete, and Figure 9 A, B, C, and D are diagrams showing the progress corresponding to the mixer drum rotation phase similar to that of FIG. 5 in the case of intermediate hardness fresh concrete with a slump of about 5 to 10 cm. 1... Vehicle body, 2... Mixer drum, 3... Drive device,
4... Engine, 5... Power extraction device, 6... Reversible variable displacement pump, 7... Hydraulic motor, 8, 9... Operator,
10... Information processing device, 11... Control motor, 12...
Rotation speed sensor, 13... Accelerator drive device, 14...
Rotational phase sensor, 15A, 15B...screw blade, 16...rear opening, 17...feed chute, 18...extension chute, 19...discharge port, 20
...Axis, 21...Cam, 22...Proximity sensor, 23...Intake, 24...Rotation speed setting, 25...Switch operation, 2
6... Intake, 28... Required work determination, 29... Reverse discharge signal, 30... Intake, 31... Comparison section, 32, 33...
Calculation, 34, 35...Output, 36...Pump actuator, 37...Display part, R, R'...Mixer drum reverse direction arrow, D...Discharge arrow, C...Ready-mixed concrete, a...Main blade, b...Discharge blade.

Claims (1)

[Claims] 1. It is rotatably mounted on the car body and connected to a drive device for forward and reverse rotation, and two helical ribbon-shaped screw blades are mounted on the inner wall to perform various tasks as it rotates, rotating at an angle of 180 degrees. For the mixer drums installed with a phase difference, a sensor is provided to detect the rotation angle phase of the mixer drum, and the signal is connected to control the rotation of the drive device via the information processing device, thereby controlling the reverse rotation of the mixer drum. The rotation speed is changed every 1/4 rotation phase, and the speed is changed to a low speed during a phase period when a large amount of fresh concrete is discharged by the screw blade, and to a high speed during a phase period when a small amount of fresh concrete is discharged by the screw blade. Mixer drum drive control device for mixer trucks.