Concrete pump device

Abstract

To provide a concrete pump device comprising a structure in which a throttle part is easy to replace.SOLUTION: A concrete pump device 1 comprises a plate-like throttle plate 8 for forming a portion of a connection oil passage connecting a raising / lowering cylinder 6 for raising / lowering a boom 3 with respect to a frame 2, and an accumulator 7 connected to the raising / lowering cylinder 6 by bolts 9. The throttle plate 8 comprises: a throttle part 81 for throttling the cross-sectional area of the connection oil passage; and a plurality of bolt through holes 82-82 used to fix a periphery of the throttle plate 8, and penetrating in a plate thickness direction. The throttle plate 8 is inserted between the raising / lowering cylinder 6 and the accumulator 7 and fixed to the raising / lowering cylinder 6 and the accumulator 7 in such a manner that the bolts 9 for fixing the accumulator 7 are made to penetrate the plurality of bolt through holes 82-82 respectively.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a concrete pump device used, for example, to pump ready-mixed concrete to a high place. [Background technology]

[0002] A known example of a concrete pump vehicle that includes a concrete pump device is the configuration described in Patent Document 1. Patent Document 1 discloses a configuration in which an accumulator (pressure storage device) is connected to the high-pressure side of a boom-raising cylinder installed between the vehicle body and the boom in order to raise and lower the boom relative to the vehicle body, and a throttle valve is installed between the boom-raising cylinder and the accumulator. With this configuration, the spring action of the accumulator and the damping action of the throttle valve can suppress boom vibrations that occur when pumping ready-mixed concrete.

[0003] However, when replacing a throttle valve or other restrictor due to deterioration over time, it can be difficult to remove the restrictor alone. For this reason, there is room for improvement in the structure, taking into account maintenance that involves replacement. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-287290 Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a concrete pump device having a structure that makes it easy to replace the throttle portion. [Means for solving the problem]

[0006] a hydraulic pump that supplies hydraulic oil to the boom; an accumulator connected to the boom-raising cylinder with bolts; and a plate-shaped restrictor plate that forms part of a connecting oil passage that links the boom-raising cylinder and the accumulator. The restrictor plate has a restricting portion that restricts the cross-sectional area of ​​the connecting oil passage, and bolt through-holes that pass through the plate thickness and are used to secure the restrictor plate to its periphery. The restrictor plate is inserted between the boom-raising cylinder and the accumulator, and the bolts for securing the accumulator are inserted through each of the bolt through-holes, thereby securing the restrictor plate to the boom-raising cylinder and the accumulator.

[0007] According to the above configuration, the restrictor provided on the restrictor plate can be replaced by removing the bolts from the bolt through holes and taking the restrictor plate out from between the elevation cylinder and the accumulator, which makes it easy to replace the restrictor. Furthermore, the bolts that fasten the accumulator and the elevation cylinder can also be used to attach the restrictor.

[0008] The throttle portion may be a valve unit incorporating a valve body that throttles the cross-sectional area of ​​the space through which the hydraulic oil passes, and the throttle plate may detachably support the valve unit.

[0009] According to this configuration, since only the valve unit can be replaced with respect to the throttle plate, the plate can be reused without replacement, thereby reducing the number of replacement parts.

[0010] Furthermore, the aperture plate, when viewed in a plane, has three or more of the bolt through holes around the aperture portion, and the aperture portion can be arranged inside a figure formed by virtual lines connecting the centers of the bolt through holes that are adjacent to each other in the circumferential direction on the aperture plate, among the three or more bolt through holes.

[0011] With this configuration, the throttle section is located inside the throttle plate from an imaginary line corresponding to the boundary where the fastening force of the bolts becomes weaker the further out from the throttle plate it is, so that even if hydraulic oil leaks from the throttle section, the leaked oil can be prevented from escaping outside the throttle plate. [Effects of the Invention]

[0012] According to the present invention, a concrete pump device can be provided which has a structure in which the throttle valve can be easily replaced by easily replacing the throttle portion and by using the same bolt. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is a schematic diagram illustrating a concrete pumping apparatus according to an embodiment of the present invention; [Figure 2] 2 is a partial cross-sectional view of the concrete pump device, showing the assembled state of the elevation cylinder, accumulator, and throttle plate, as viewed from the side of the state shown in FIG. 1.

[0023] FIG. [Figure 3] FIG. 3 is an enlarged view of the area enclosed by III in FIG. 2. [Figure 4] 4A and 4B show the aperture plate, in which FIG. 4A is a plan view and FIG. 4B is a cross-sectional view taken along the line IVb in FIG. [Figure 5] FIG. 10 is a plan view showing a modified example of the aperture plate. DETAILED DESCRIPTION OF THE INVENTION

[0014] Next, the present invention will be described by taking up a concrete pumping device 1 according to an embodiment. An outline of the basic configuration of a concrete pump truck, which is an example of a vehicle equipped with a concrete pump device 1, is described below. As shown in Fig. 1, a concrete pump truck is equipped with a boom 3, which is made up of multiple beams 31-31 bendably connected to a base 2 mounted on a chassis or the like (not shown), and is a vehicle that can pump ready-mixed concrete to high places or remote locations by extending the boom 3 using multiple hydraulic cylinders 4.

[0015] The concrete pumping device 1 mainly comprises a base 2, a boom 3, a concrete pipe 5, a concrete pump (not shown), a hoisting cylinder 6, and a hydraulic pump (not shown). The boom 3 is capable of raising and lowering and extending relative to the base 2, and is also capable of rotating horizontally relative to the base 2. FIG. 1 shows a closed state in which multiple beams 31 are mutually bent and folded. A concrete pipe 5 is provided on the side of the boom 3 (part of which penetrates the boom 3 in the width direction). Therefore, the boom 3 supports the concrete pipe 5.

[0016] In the case of a concrete pump truck, ready-mixed concrete supplied from a concrete mixer truck (not shown) is fed into a hopper (not shown) located at the rear of the concrete pump device 1, and the ready-mixed concrete in the hopper is sent to a concrete pipe 5 by a concrete pump mounted on a chassis or the like (not shown), and the delivered ready-mixed concrete is passed through the concrete pipe 5. The ready-mixed concrete can then be discharged from the opening at the tip of the concrete pipe 5 located at the pouring location.

[0017] As shown in FIG. 1, the boom 3 of this embodiment is configured by four beams 31 connected at three joints so that they can bend alternately. Adjacent beams 31 are connected to each other at the end of each beam 31. A derrick cylinder 6, which is a hydraulic cylinder, is connected to the boom 3. The derrick cylinder 6 uses hydraulic pressure to raise and lower the boom 3 (more specifically, the beam 31 on the base end side) relative to the base 2. When the derrick cylinder 6 extends, the boom 3 moves so as to rise, and when the derrick cylinder 6 retracts, the boom 3 moves so as to fall. A hydraulic pump supplies hydraulic oil to the derrick cylinder 6 for raising and lowering the boom 3.

[0018] The boom raising cylinder 6 is provided with an accumulator (pressure storage device) 7, as shown in Figures 1 and 2. This accumulator 7 has a long shape and is a piston-type accumulator, which is a device in which a mechanism (specifically, a piston) that performs reciprocating motion is housed inside a case (housing, exterior, etc.). This accumulator 7 is fixed to the boom raising cylinder 6 so that its longitudinal direction is aligned with the longitudinal direction of the boom raising cylinder 6. An oil passage in the accumulator 7 is connected to the high-pressure side end of the boom raising cylinder 6.

[0019] Next, we will explain the vibration of the boom 3 and its effects. When the concrete pump is operating, the pumped fresh concrete collides with the fresh concrete remaining inside the concrete pipe 5, generating pulsations. These pulsations cause vibrations in the boom 3. The vibrations generated in the boom 3 are transmitted to the derrick cylinder 6 connected to the boom 3, causing it to extend or retract. The accumulator 7 temporarily stores hydraulic oil that flows out of the derrick cylinder 6 when it retracts. In addition, the cross-sectional area of ​​the connecting oil passage L between the derrick cylinder 6 and the accumulator 7 is restricted by the restrictor portion 81 of the restrictor plate 8 (described later), restricting the flow of hydraulic oil in the direction of outflow from the derrick cylinder 6. Therefore, the spring action of the accumulator 7 combined with the damping action of the restrictor portion 81 absorbs vibrations generated in the boom 3. Therefore, compared to when the accumulator 7 is not provided, the vibration of the boom 3 during operation of the concrete pump can be reduced.

[0020] In the concrete pumping device 1 of this embodiment, the accumulator 7 is connected to the derricking cylinder 6 by a bolt 9. Although only the bolt head is visible in FIG. 2, the bolt 9 is actually screwed in from the accumulator 7 side toward the derricking cylinder 6. Multiple bolts 9 are used per connection point. In this embodiment, four bolts 9 to 9 are used, each connecting and fixing the derricking cylinder 6 and the accumulator 7.

[0021] The concrete pump apparatus 1 of this embodiment is equipped with a plate-shaped throttle plate 8. The throttle plate 8 of this embodiment is rectangular as shown in FIG. 4(a), but the planar shape of the throttle plate 8 is not particularly limited. The throttle plate 8 is provided to form a part of the connecting oil passage L connecting the hoisting cylinder 6 and the accumulator 7. The throttle plate 8 includes a throttle section 81 that throttles the cross-sectional area of ​​the connecting oil passage L and a plurality of bolt through holes 82-82 that penetrate the throttle plate 8 in the thickness direction and are used to fix the throttle plate 8 to the periphery. As shown in FIG. 3, the throttle section 81 is a valve unit 81U incorporating a valve element 811 that throttles the cross-sectional area of ​​the space through which the hydraulic oil passes. The throttle section 81 is a part of the flow path through which the hydraulic oil actually flows in the connecting oil passage L belonging to the throttle plate 8, where the flow path is throttled by having a cross-sectional area smaller than that of the flow path through which the hydraulic oil actually flows in the connecting oil passage L belonging to the hoisting cylinder 6. As shown in Figures 4(a) and 4(b), a threaded hole 83 with an internal thread is formed in the center of the throttle plate 8 in a plan view. The valve unit 81U is screwed into the threaded hole 83, thereby being fixed to the throttle plate 8, as shown in Figure 2. Seal members 84 are provided at both ends of the throttle plate 8 in the thickness direction, surrounding the connecting oil passage L to prevent hydraulic oil leakage (see Figure 3). The throttle plate 8 is inserted between the elevation cylinder 6 and the accumulator 7, and is fixed to the elevation cylinder 6 and the accumulator 7 by passing the bolts 9 for fixing the accumulator 7 described above through the respective bolt through holes 82 ("co-fastening").

[0022] The throttle section 81 is a valve unit 81U incorporating a valve element 811 (see FIG. 3) that throttles the cross-sectional area of ​​the space through which the hydraulic oil passes. As described above, the valve unit 81U is fixed to the throttle plate 8 with screws, so that the throttle plate 8 detachably supports the valve unit 81U. Because the throttle plate 8 is configured in this way, by removing the valve unit 81U from the throttle plate 8, it is possible to replace only the valve unit 81U with respect to the throttle plate 8, and therefore the plate can be reused without replacement. This has the advantage of reducing the number of replacement parts related to the throttle of the connecting oil passage L.

[0023] In the plan view (viewed in the plate thickness direction) shown in FIG. 4(a), the drawn plate 8 has three or more bolt through holes 82 around the drawn portion 81. The drawn plate 8 of this embodiment has four bolt through holes 82. Note that, for example, as shown in FIG. 5, the three bolt through holes 82 may be arranged in a triangular shape, and the number of bolt through holes 82 is not particularly limited. The drawn portion 81 is arranged inside a shape (a rectangle in this embodiment (FIG. 4(a)) and a triangle in the modified embodiment (FIG. 5)) formed by a virtual line VL (shown by a dashed line in FIGS. 4(a) and 4(b) and 5) connecting the centers of the bolt through holes 82, 82 that are adjacent in the circumferential direction of the drawn plate 8 among the three or more bolt through holes 82. In this positional relationship, in the drawn plate 8 with the drawn portion 81 provided, the bolt through holes 82 are lined up in the circumferential direction with the drawn portion 81 as the reference (centered on the axis of the drawn portion 81). With this positional relationship, the restrictor section 81 is located inside the restrictor plate 8 of the imaginary line VL (where the securing force is greatest on the imaginary line VL), which corresponds to the boundary where the securing force applied by the bolts 9 to the respective suction cylinder 6, suction plate 8, and accumulator 7 weakens toward the outside of the suction plate 8 in a plan view. Even if a malfunction of the valve unit 81U or other problem causes hydraulic oil to leak from the restrictor section 81, the hydraulic oil can be stopped at the portion of the imaginary line VL where the securing force is greatest, thereby preventing the leaked oil from leaking outside the suction plate 8. The positional relationship described above applies only if the larger diameter of the through-hole 82 on the accumulator 7 side or the suction cylinder 6 side is located inside the imaginary line VL. That is, the outermost radial end of the connecting oil passage L in the suction plate 8, surrounded by the seal member 84 (see FIG. 3), is located inside the imaginary line VL (see FIG. 4(b)) (within the figure).

[0024] In the concrete pump device 1 of this embodiment configured as described above, the throttle portion 81 provided on the throttle plate 8 can be replaced by removing the bolts 9 from the bolt through holes 82 and taking out the throttle plate 8 from between the derricking cylinder 6 and the accumulator 7, making it easy to replace the throttle valve. Furthermore, the bolts 9 that fasten the accumulator 7 and the derricking cylinder 6 can also be used to attach the throttle portion 81, thereby reducing the number of component parts.

[0025] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment. For example, the valve unit 81U may be fixed to the aperture plate 8 in an undetachable manner, forming a completely integrated structure. In this case, when it becomes necessary to replace the valve unit 81U, the entire aperture plate 8 can be replaced.

[0026] Furthermore, the valve unit 81U may have a variable aperture ratio.

[0027] In addition, the accumulator 7 and the throttle portion 81 may be connected to the low pressure side of the elevation cylinder 6.

[0028] Furthermore, when the valve unit 81U is integrated with the throttling plate 8 for the throttling section 81, it is sufficient that at least the oil passage portion of the valve unit 81U is positioned within the figure formed by the imaginary line VL connecting the centers of the bolt through holes 82, 82 that are adjacent to each other in the circumferential direction.

[0029] Furthermore, in the above embodiment, the concrete pump device 1 is provided on a concrete pump vehicle, but the present invention is not limited to this, and the concrete pump device 1 may be provided on a distributor installed on the ground. [Explanation of symbols]

[0030] 1. Concrete pumping equipment 2 Mounting stand 3. Boom 31 Beam 4 hydraulic cylinders 5. Concrete piping 6. Drilling cylinder 7 Accumulator 8 Aperture plate 9 volts 81 Constriction section 81U Valve Unit 811 Valve body 82 Bolt through holes 83 screw holes 84 Sealing material L connecting oil passage VL Virtual Line

Claims

1. A stand and Concrete pipes through which fresh concrete passes, a boom mounted on the frame, supporting the concrete pipe, and rising and falling relative to the frame; a concrete pump that delivers fresh concrete to the concrete pipe; a hydraulic cylinder connected to the boom, which hydraulically raises and lowers the boom relative to the base; a hydraulic pump for supplying hydraulic oil to the elevation cylinder; an accumulator connected to the elevation cylinder by bolts; a plate-shaped throttle plate for forming a part of a connecting oil passage connecting the elevation cylinder and the accumulator; the restrictor plate includes a restrictor portion that restricts a cross-sectional area of ​​the connecting oil passage, and a plurality of bolt through holes that are used for fixing the restrictor plate to a periphery and that penetrate the restrictor plate in a plate thickness direction, The throttle plate is inserted between the elevation cylinder and the accumulator, and the bolts for fixing the accumulator are inserted through each of the plurality of bolt through holes, thereby fixing the throttle plate to the elevation cylinder and the accumulator.

2. The throttle portion is a valve unit incorporating a valve body that throttles the cross-sectional area of ​​a space through which the hydraulic oil passes, 2. The concrete pumping apparatus of claim 1, wherein the throttle plate removably supports the valve unit.

3. the aperture plate has three or more of the bolt through holes around the aperture portion in a plan view, 3. The concrete pump device according to claim 1, wherein the constriction portion is arranged within a figure formed by virtual lines connecting the centers of the bolt through holes that are adjacent to each other in the circumferential direction on the constriction plate, among the three or more bolt through holes.

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