Concrete piping

Abstract

The present invention provides a concrete piping system that prevents the packing member from being pulled towards the center of the pipe when negative pressure is generated inside the pipe during the pumping of ready-mix concrete. [Solution] The concrete piping is a concrete piping for transporting ready-mix concrete pumped from a concrete pump, and comprises a pipe body and an annular packing member attached to the connecting end of the pipe body, the packing member comprising an elastic part made of an elastic material and an annular reinforcing part that reinforces the elastic part, the reinforcing part forming a part of the surface of the packing member and having an exposed surface that contacts the pipe body.

Description

Technical Field

[0001] The present invention relates to concrete pipes.

Background Art

[0002] For example, Patent Document 1 discloses a connection structure for connecting concrete pipes that transport fresh concrete pumped from a concrete pump to each other. In this connection structure, by providing a packing member at the connection end of the concrete pipe, leakage of fresh concrete from the connection part is prevented.

[0003] By the way, in a concrete pipe, a negative pressure is generated in the pipe due to the pulsation caused by pumping fresh concrete with a concrete pump, and the packing member is drawn into the pipe center direction. As a result, there was a risk that the packing member would rotate or shift from its initial position along with the rotation.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, the problem is to provide a concrete pipe that can prevent the packing member from being drawn into the pipe center direction when a negative pressure is generated in the pipe during pumping of fresh concrete.

Means for Solving the Problems

[0006] The concrete pipe is a concrete pipe that transports fresh concrete pumped from a concrete pump, comprising a pipe body and an annular packing member attached to the connection end of the pipe body. The packing member comprises an elastic portion made of an elastic material and an annular reinforcing portion that reinforces the elastic portion. The reinforcing portion constitutes a part of the surface of the packing member and has an exposed surface that contacts the pipe body. [Brief explanation of the drawing]

[0007] [Figure 1] Perspective view of a concrete pump vehicle according to one embodiment. [Figure 2] Left side view of a concrete pump vehicle according to the same embodiment. [Figure 3] Plan view of the pump unit according to the same embodiment. [Figure 4] A schematic plan view showing the pump unit according to the same embodiment. [Figure 5] Figure 3 shows a cross-sectional view of the main part of the VV line. [Figure 6] Figure 5: Enlarged view of area VI [Figure 7] Cross-sectional view of the main section along line VII-VII in Figure 3. [Figure 8] Schematic diagram of the pump unit and drive unit according to the same embodiment. [Figure 9] Cross-sectional view of the main part of an S-shaped valve according to another embodiment. [Figure 10] Cross-sectional view of the main part of an S-shaped valve according to another embodiment. [Modes for carrying out the invention]

[0008] In each drawing, the dimensions of components may be enlarged or reduced from their actual dimensions for the sake of clarity, and the dimensional ratios between drawings may not be consistent. Furthermore, in each drawing, some components may be omitted for the sake of clarity.

[0009] Terms including ordinal numbers such as "1st," "2nd," etc., are used to describe various components, but these terms are used solely for the purpose of distinguishing one component from others, and the components are not particularly limited by these terms. Furthermore, the number of components including ordinal numbers is not particularly limited; for example, there may be only one. Also, the ordinal numbers used in the following specification and drawings may differ from the ordinal numbers described in the claims.

[0010] Furthermore, in the following explanation, the first direction (first horizontal direction) D1 is also called the front-back direction D1, and of the first direction D1, the direction of the arrow in the diagram is defined as the front direction, and the direction opposite to the direction of the arrow in the diagram is defined as the back direction. Also, the second direction (second horizontal direction) D2 is also called the left-right direction D2, and of the second direction D2, the direction of the arrow in the diagram is defined as the left direction, and the direction opposite to the direction of the arrow in the diagram is defined as the right direction. Also, the third direction D3 is also called the up-down direction D3, and of the third direction D3, the direction of the arrow in each diagram is defined as the up direction, and the direction opposite to the direction of the arrow in each diagram is defined as the down direction.

[0011] The following description will explain one embodiment of concrete piping with reference to Figures 1 to 8. Note that the following embodiment is provided as an example to aid in understanding the structure of concrete piping, and is not intended to limit the structure of concrete piping.

[0012] First, before explaining concrete piping, we will describe concrete pump vehicles with reference to Figures 1 to 4. Note that the configuration of a concrete pump vehicle is not limited to the following configurations.

[0013] As shown in Figures 1 and 2, the concrete pump vehicle 1 may include a frame 2, a pump unit 3 mounted on the frame 2 for pumping ready-mix concrete, a drive unit 4 for driving the pump unit 3, a control device 5 for controlling each of the parts 3 and 4, and a running unit 6 rotatably attached to the frame 2. Note that the concrete pump vehicle 1 does not have a power source for driving and is a towed vehicle that is towed by another towing vehicle.

[0014] The running gear 6 may include a pair of left and right wheels 61, 61 and an axle 62 connecting the wheels 61, 61. The axle 62 is freely rotatably supported at the bottom of the frame 2. That is, the wheels 61, 61 are non-driven wheels. As shown in FIG. 2, the running gear 6 is disposed slightly rearward of the center in the front-rear direction D1 of the frame 2.

[0015] The frame 2 may include a pair of main frames 21, 21 extending in the front-rear direction D1 and a front frame 22 connecting the front ends of the main frames 21, 21. Further, the frame 2 may include a plurality of cross frames 23 (see FIG. 2) extending in the left-right direction D2 and connecting the pair of main frames 21, 21. The cross frame 23 is fixed to the lower surface of the main frame 21, for example, by welding or the like.

[0016] Further, the frame 2 may include legs 24 fixed to the side surfaces of the main frames 21. The legs 24 may be, for example, jacks that extend to the ground during the concrete placement work. A plurality of legs 24 may be provided in the front-rear direction D1 as in this embodiment. As shown in FIG. 2, the legs 24 are provided at the same position as the cross frame 23 in the front-rear direction D1.

[0017] The frame 2 may include a towed portion 25 provided at the front end of the front frame 22. The towed portion 25 may be, for example, an annular hitch as shown in FIG. 1.

[0018] As shown in FIG. 3, the pump unit 3 may include a concrete pump 7 and a valve device 8 disposed behind the concrete pump 7.

[0019] The concrete pump 7 includes a first concrete cylinder 71 on the left side and a second concrete cylinder 72 on the right side arranged in the left-right direction D2.

[0020] Furthermore, the concrete pump 7 includes a first drive cylinder 73 that is axially connected to the base (front) end of the first concrete cylinder 71 via a center frame 75 and drives the first concrete cylinder 71. Similarly, the concrete pump 7 includes a second drive cylinder 74 that is axially connected to the base (front) end of the second concrete cylinder 72 via a center frame 75 and drives the second concrete cylinder 72.

[0021] As shown in Figure 4, the concrete pump 7 includes first and second concrete pistons 71a and 72a slidably fitted into first and second concrete cylinders 71 and 72, and first and second drive pistons 73a and 74a slidably fitted into first and second drive cylinders 73 and 74. The first concrete piston 71a and the first drive piston 73a are connected by a first piston rod 76 that slidably passes through the center frame 75, and the second concrete piston 72a and the second drive piston 74a are connected by a second piston rod 77 that slidably passes through the center frame 75. Each drive piston 73a and 74a divides the drive cylinders 73 and 74 into rod-side hydraulic oil chambers 73b and 74b and head-side hydraulic oil chambers 73c and 74c. The front (rear end) of each concrete cylinder 71, 72 is open as a discharge end 71b, 72b. The discharge ends 71b, 72b of each concrete cylinder 71, 72 are connected to and communicate with the front of the valve device 8.

[0022] The concrete pump 7 may include a center box 78 surrounding the first and second concrete cylinders 71 and 72, as shown in Figure 3. The center box 78 is a rectangular tube extending in the front-rear direction D1. The front end of the center box 78 is connected to the center frame 75, and the rear end is connected to the valve device 8.

[0023] The valve device 8 comprises a valve casing 81, a bottom cover 82, an S-shaped valve 83, an S-shaped valve driving means 84, and a discharge pipe 85. A hopper 86 (see Figure 2) for receiving ready-mix concrete is connected to the upper part of the valve casing 81. The valve casing 81 is formed in a frame shape by a front wall 81a, a rear wall 81b, and both side walls 81c, and its lower part is open by an opening. The bottom cover 82 opens and closes the opening at the bottom of the valve casing 81, for example, by a cylinder 87 (see Figure 2).

[0024] The front wall 81a of the valve casing 81 may be provided with a wear plate 88, as shown in Figure 7. The wear plate 88 is an eight-shaped plate member with two through holes formed therein. The two through holes of the wear plate 88 communicate with the concrete cylinders 71 and 72.

[0025] As shown in Figures 3 to 5, a curved tubular S-shaped valve 83 is housed in the lower part of the valve casing 81. The S-shaped valve 83 is an example of concrete piping and transports ready-mix concrete pumped from the concrete pump 7.

[0026] As shown in Figure 5, the S-shaped valve 83 has an S-shaped passage formed inside and is equipped with an inlet 83b and a discharge port 83c. In this embodiment, the central axis of the S-shaped passage is defined as the pipe axis of the S-shaped valve 83, and the direction in which the central axis of the S-shaped passage extends is defined as the pipe axis direction of the S-shaped valve 83.

[0027] The S-shaped valve 83 is integral with the S-shaped valve 83 and is rotatable around the axis of a pivot shaft 83s parallel to the axis of each concrete cylinder 71, 72, and is configured to alternately switch the discharge ends 71b, 72b of the pair of concrete cylinders 71, 72 and the intake port 83b into communication.

[0028] The valve device 8 may include a sliding member 89 connected to the S-shaped valve 83. The sliding member 89 may be an annular wear ring 89. The wear ring 89 slides against a wear plate 88 connected to the discharge ends 71b and 72b of the concrete cylinders 71 and 72. Therefore, it is preferable that the wear ring 89 and the wear plate 88 are wear-resistant and fixed in a replaceable manner.

[0029] As shown in Figures 5 and 6, the S-shaped valve 83 may comprise a valve body 83a and an annular packing member 9 attached to the connecting end of the valve body 83a. A wear ring 89 is connected to the valve body 83a. The packing member 9 prevents fresh concrete from leaking between the valve body 83a and the wear ring 89. The packing member 9 also mitigates the impact between the valve body 83a and the wear ring 89.

[0030] The connecting end (in this case, the front end) of the valve body 83a may be provided with an annular groove 83d that is recessed inward in the axial direction of the valve body 83a. The outer end face of the annular groove 83d may be located further outward in the axial direction than the inner end face of the annular groove 83d. The outer end face of the annular groove 83d is in contact with the wear ring 89, and the inner end face of the annular groove 83d sandwiches the packing member 9 together with the wear ring 89.

[0031] The packing member 9 may have a T-shaped cross-section. That is, the packing member 9 may comprise a cylindrical portion 9a and a hollow disc portion 9b connected to the inner circumferential surface of the cylindrical portion 9a. The cylindrical portion 9a may have a first fitting portion 9c that fits into the annular groove 83d. The cylindrical portion 9a may also have a second fitting portion 9d that fits into a recess formed between a stepped portion 89a formed in the wear ring 89 and the valve body 83a. As a result, when negative pressure is generated inside the S-shaped valve 83, the first fitting portion 9c is locked into the annular groove 83d and the second fitting portion 9d is locked into the stepped portion 89a, thereby preventing the packing member 9 from being pulled towards the center of the S-shaped valve 83.

[0032] The packing member 9 comprises an elastic portion 91 made of an elastic material and an annular reinforcing portion 92 embedded in the elastic portion 91. The elastic portion 91 is made of, for example, rubber. The reinforcing portion 92 is made of a material harder than the elastic material constituting the elastic portion 91. The reinforcing portion 92 is made of, for example, a metal such as stainless steel. The packing member 9 can be formed by mold molding, in which the reinforcing portion 92 is placed in a mold (not shown), and rubber forming the elastic portion 91 is injected into the mold and solidified.

[0033] Because the packing member 9 is equipped with a reinforcing portion 92, when negative pressure is generated inside the S-shaped valve 83, the elastic portion 91 deforms toward the center of the S-shaped valve 83, but the reinforcing portion 92 is less likely to deform toward the center of the S-shaped valve 83, thus preventing the packing member 9 from being pulled toward the center of the S-shaped valve 83. Furthermore, as shown in Figure 6, because there is also an elastic portion 91 on the outer circumference side of the reinforcing member 92, even when negative pressure is generated inside the S-shaped valve 83, the elastic portion 91 on the outer circumference side of the reinforcing member 92 is particularly less likely to deform.

[0034] The elastic portion 91 may include an annular recess 91a. The recess 91a is formed to open at the inner end of the first fitting portion 9c in the axial direction of the pipe. The recess 91a has a rectangular cross-section.

[0035] The reinforcing portion 92 is an annular member having a rectangular cross-section. The reinforcing portion 92 is positioned in the recess 91a and is partially exposed. At the inner end of the first fitting portion 9c in the direction of the pipe axis, the reinforcing portion 92 and the elastic portion 91 are flush. That is, the reinforcing portion 92 constitutes a part of the surface of the packing member 9 and has an exposed surface 92a that contacts the valve body 83a. The exposed surface 92a may, for example, contact the bottom of the annular groove 83d, as in this embodiment. Because the reinforcing portion 92 contacts the valve body 83a (specifically the bottom of the annular groove 83d), the reinforcing portion 92 is less likely to deform even when negative pressure is generated inside the S-shaped valve 83, and the contact area of ​​the reinforcing portion 92 with the valve body 83a is maintained. As a result, even when negative pressure is generated inside the S-shaped valve 83, it is possible to suppress the packing member 9 from rotating or shifting from its initial position due to rotation.

[0036] The reinforcing portion 92 extends outward in the direction of the pipe axis from the exposed surface 92a, penetrating the first fitting portion 9c. As a result, when viewed radially from the valve body 83a, the reinforcing portion 92 overlaps with the annular groove 83d. The length of the reinforcing portion 92 in the direction of the pipe axis may be at least half or more of the length of the cylindrical portion 9a in the direction of the pipe axis. Also, when viewed radially from the valve body 83a, the reinforcing portion 92 may overlap with the hollow disc portion 9b. Because the reinforcing portion 92 is embedded in the first fitting portion 9c, the first fitting portion 9c is reinforced by the reinforcing portion 9c, so that when negative pressure is generated inside the S-shaped valve 83, the packing member 9 is effectively prevented from being pulled toward the center of the S-shaped valve 83.

[0037] On the other hand, the end of the reinforcing portion 92 opposite to the exposed surface 92a terminates at the middle of the cylindrical portion 9a, and the reinforcing portion 92 does not contact the bottom of the stepped portion 89a. As a result, the packing member 9 is prevented from rotating relative to the valve body 83a, but rotation relative to the wear ring 89 is permitted to a certain extent. Consequently, the rotation of the packing member 9 in conjunction with the rotation of the wear ring 89 can be suppressed.

[0038] The pivot shaft 83s is connected to an S-shaped valve driving means 84 for rotating the pivot shaft 83s in sync with the operation of both concrete pistons 71a and 72a to drive the S-shaped valve 83 in a switching manner. This S-shaped valve driving means 84 is configured such that the tips of a left-side single-acting valve driving cylinder 84a and a right-side single-acting valve driving cylinder 84b, which work together, are connected via a connecting arm (not shown) that extends integrally from the pivot shaft 83s, and the base ends of both valve driving cylinders 84a and 84b are rotatably connected to the valve casing 81.

[0039] During operation of the pump unit 3, the pair of valve drive cylinders 84a and 84b alternately connect the first and second concrete cylinders 71 and 72 that are in the concrete suction state to the valve casing 81, and the one that is in the concrete pumping state to the suction port 83b, thereby smoothly pumping the concrete. Specifically, the S-shaped valve 83 is capable of reciprocating (oscillating) between a first switching position (shown by a solid line in Figure 4) where the suction port 83b is connected to the discharge end 71b of the first concrete cylinder 71, and a second switching position (shown by a dashed line in Figure 4) where the suction port 83b is connected to the discharge end 72b of the second concrete cylinder 72. The first switching position is achieved by the extension of the left valve drive cylinder 84a, and the second switching position is achieved by the extension of the right valve drive cylinder 84b.

[0040] The discharge pipe 85 has its front end connected to the rear wall 81b of the valve casing 81 and is in constant communication with the S-shaped valve 83, and its rear end is connected to a hose or the like (not shown).

[0041] The pump unit 3 may also include a hydraulic pump 10 that supplies hydraulic fluid to the concrete pump 7, and a valve 11 (see Figure 8) that connects the hydraulic pump 10 and the concrete pump 7. The pump unit 3 may also include an oil tank 12 and an oil cooler 13 (see Figures 1 and 2).

[0042] The hydraulic pump 10 may include a pump 10a for a first drive cylinder and a pump 10b for a second drive cylinder. The pump unit 3 may also include an auxiliary pump 10c connected coaxially to the second drive cylinder pump 10b. The auxiliary pump 10c supplies hydraulic fluid to, for example, an S-shaped valve driving means 84 (valve drive cylinders 84a, 84b).

[0043] As shown in Figure 8, the pump unit 3 has the pumps 10a and 10b for the first and second drive cylinders connected to the first and second drive cylinders 73 and 74 by a valve 11, and the hydraulic fluid discharged from the pumps 10a and 10b for the first and second drive cylinders operates the first and second drive cylinders 73 and 74.

[0044] The drive unit 4 drives the pump unit 3. Specifically, the drive unit 4 drives the first and second drive cylinder pumps 10a, 10b and the auxiliary pump 10c. As shown in Figures 2 and 8, the drive unit 4 may include a first motor 4a connected to the first drive cylinder pump 10a and a second motor 4b connected to the second drive cylinder pump 10b.

[0045] The drive unit 4 is fixed on the frame 2, as shown in Figures 1 and 2. Specifically, the drive unit 4 is fixed on a bracket that connects the upper surfaces of a pair of main frames 21, 21.

[0046] As shown in Figure 2, the drive unit 4 is located at the front of the frame 2. That is, the drive unit 4 is located between the towed section 25 and the running section 6 in the longitudinal direction D1. By placing the heavy drive unit 4 (motors 4a, 4b) close to the towed section 25, the load is applied to the towed section 25, so that the concrete pump vehicle 1 is towed in a stable state.

[0047] Furthermore, the drive unit 4 may be positioned directly above the legs 24 attached to the frame 2. In this embodiment, the drive unit 4 is positioned directly above the front legs 24. Here, positioning the drive unit 4 directly above the legs 24 means that the drive unit 4 and the legs 24 are positioned so that they overlap in the vertical direction D3. By positioning the drive unit 4 directly above the legs 24, a load is applied to the legs 24, thus stabilizing the concrete pump vehicle 1 during concrete placement work.

[0048] The control device 5 controls at least the pump unit 3 and the drive unit 4. The control device 5 may include first and second control panels 51 and 52 arranged in the left-right direction D2, as shown in Figure 1. The control panels 51 and 52 are equipped with converters, etc. The control device 5 (control panels 51 and 52) is positioned behind the travel unit 6, as shown in Figure 2. As a result, the heavy drive unit 4 and the control device 5 are positioned so as to sandwich the travel unit 6 in the front-rear direction D1, thus achieving good balance between the front and rear of the travel unit 6.

[0049] [1] Based on the above, the concrete piping is as shown in this embodiment. A concrete pipe (S-shaped valve in this embodiment) 83 for transporting fresh concrete pumped from a concrete pump 7, The system comprises a piping body (in this embodiment, a valve body) 83a and an annular packing member 9 attached to the connecting end of the piping body (in this embodiment, a valve body) 83a, The packing member 9 comprises an elastic portion 91 made of an elastic material and an annular reinforcing portion 92 that reinforces the elastic portion 91. The reinforcing portion 92 constitutes a part of the surface of the packing member 9 and has an exposed surface 92a that contacts the piping body (in this embodiment, the valve body) 83a. This configuration is preferable.

[0050] With this configuration, the packing member 9 is equipped with a reinforcing portion 92. When negative pressure is generated inside the concrete pipe (in this embodiment, an S-shaped valve) 83, the elastic portion 91 deforms toward the center of the pipe, but the reinforcing portion 92 is less likely to deform toward the center of the pipe. This prevents the packing member 9 from being pulled toward the center of the pipe.

[0051] [2] Furthermore, in the concrete piping (S-shaped valve in this embodiment) 83 of [1] above, as in this embodiment, The elastic portion 91 includes an annular recess 91a, The reinforcing portion 92 is positioned in the recess 91a, and the exposed surface 92a is exposed at the opening of the recess 91a. This configuration is preferable.

[0052] With this configuration, the reinforcing portion 92 is surrounded by the elastic portion 91 except for the exposed surface 92a, and thus becomes integrated with the elastic portion 91, allowing it to properly reinforce the packing member 9. Furthermore, there is no need to fix the reinforcing portion 92 to the elastic portion 91 with adhesive or the like.

[0053] [3] Furthermore, in the concrete piping (S-shaped valve in this embodiment) 83 of [1] or [2] above, as in this embodiment, The connection end of the piping body (in this embodiment, the valve body) 83a is provided with an annular groove 83d that is recessed inward in the axial direction of the piping body (in this embodiment, the valve body) 83a. The packing member 9 includes a fitting portion (in this embodiment, a first fitting portion) 9c that fits into the annular groove 83d. This configuration is preferable.

[0054] With this configuration, when negative pressure is generated inside the concrete pipe (S-shaped valve in this embodiment) 83, the fitting portion (first fitting portion in this embodiment) 9c is locked into the annular groove 83d, thereby preventing the packing member 9 from being pulled towards the center of the pipe.

[0055] [4] Furthermore, in the concrete piping (S-shaped valve in this embodiment) 83 described in [3] above, as in this embodiment, The exposed surface 92a is in contact with the bottom of the annular groove 83d, The reinforcing portion 92 extends outward from the exposed surface 92a in the direction of the pipe axis, passing through the fitting portion (first fitting portion in this embodiment) 9c. This configuration is preferable.

[0056] With this configuration, since the first fitting portion 9c is reinforced by the reinforcing portion 92, when negative pressure is generated inside the concrete pipe (S-shaped valve in this embodiment) 83, the packing member 9 can be effectively prevented from being pulled towards the center of the pipe.

[0057] It should be noted that the concrete piping is not limited to the configuration of the embodiment described above, nor is it limited to the effects and benefits described above. Furthermore, it goes without saying that the concrete piping can be modified in various ways without departing from the spirit of the present invention. For example, one or more of the configurations and methods described below may be arbitrarily selected and adopted in the configurations and methods of the embodiment described above.

[0058] (A) In the S-shaped valve 83 according to the above embodiment, the exposed surface 92a of the reinforcing portion 92 is in contact with the bottom of the annular groove 83d of the valve body 83a. However, the S-shaped valve 83 is not limited to this configuration. The exposed surface 92a of the reinforcing portion 92 may be in contact with a part of the valve body 83a other than the bottom of the annular groove 83d. For example, as shown in Figures 9 and 10, the exposed surface 92a of the reinforcing portion 92 may be in contact with the inner surface of the valve body 83a that is on the outer side of the annular groove 83d. In the example shown in Figure 9, it is preferable that the reinforcing portion 92 is fixed to the elastic portion 91 with an adhesive or the like.

[0059] (B) In the S-shaped valve 83 according to the above embodiment, the elastic portion 91 is provided with an annular recess 91a having a rectangular cross-section, the reinforcing portion 92 is arranged in the recess 91a, and the exposed surface 92a is exposed at the opening of the recess 91a. However, the S-shaped valve 83 is not limited to this configuration. The recess 91a may have a cross-section other than rectangular. For example, the recess 91a may have a cross-section as shown in Figure 10.

[0060] (C) In the S-shaped valve 83 according to the above embodiment, the reinforcing portion 92 is an annular member having a rectangular cross-section. However, the S-shaped valve 83 is not limited to this configuration. The reinforcing portion 92 may also be an annular member having a circular or elliptical cross-section. In this case as well, a portion of the reinforcing portion 92 is exposed and in contact with the valve body 83a.

[0061] (D) In ​​the above embodiment, an S-shaped valve 83 is described as an example for concrete piping, but it is not limited to this. The concrete piping may be anything other than an S-shaped valve 83, as long as it transports the ready-mix concrete pumped from the concrete pump 7. The concrete piping may be a straight pipe, such as boom piping installed on the boom of a concrete pump vehicle.

[0062] (E) In the above embodiment, the packing member 9 is attached to the connection end between the concrete pipe (S-shaped valve 83) and the sliding member 89, but it is not limited to this. The packing member 9 may also be attached to the mutual connection ends between two concrete pipes.

[0063] (F) In addition, concrete piping may be equipped with a ring (so-called O-ring) in addition to the packing member 9.

[0064] (G) In the concrete pump vehicle 1 according to the above embodiment, the pump unit 3 is configured to pump fresh concrete using concrete pistons 71a and 72a. However, the concrete pump vehicle 1 is not limited to this configuration. For example, the pump unit 3 may be configured to pump fresh concrete by squeezing a flexible tube (pumping tube) with rollers. In other words, the method of pumping fresh concrete may be either piston type or squeeze type.

[0065] (H) Furthermore, the concrete pump vehicle 1 according to the above embodiment is configured to be a towed vehicle that is towed by another towing vehicle. However, the concrete pump vehicle 1 is not limited to this configuration. For example, the concrete pump vehicle 1 may be a vehicle equipped with a power source for driving. [Explanation of symbols]

[0066] 1...Concrete pump vehicle, 2...Frame, 3...Pump unit, 4...Drive unit, 4a...First motor, 4b...Second motor, 5...Control device, 6...Traction unit, 7...Concrete pump, 8...Valve device, 9...Packing member, 9a...Cylindrical part, 9b...Hollow disc part, 9c...First fitting part, 9d...Second fitting part, 10...Hydraulic pump, 10a...Pump for first drive cylinder, 10b...Pump for second drive cylinder, 10c...Auxiliary pump, 11...Val B, 12…Oil tank, 13…Oil cooler, 21…Main frame, 22…Front frame, 23…Side frame, 24…Legs, 25…Towed section, 51…First control panel, 52…Second control panel, 61…Wheels, 62…Axles, 71…First concrete cylinder, 71a…First concrete piston, 71b…Discharge end, 72…Second concrete cylinder, 72a…Second concrete piston, 72b…Discharge end, 73…First drive cylinder 73a...First drive piston, 73b...Rod-side hydraulic fluid chamber, 73c...Head-side hydraulic fluid chamber, 74...Second drive cylinder, 74a...Second drive piston, 74b...Rod-side hydraulic fluid chamber, 74c...Head-side hydraulic fluid chamber, 75...Center frame, 76...First piston rod, 77...Second piston rod, 78...Center box, 81...Valve casing, 81a...Front wall, 81b...Rear wall, 81c...Side wall, 82...Bottom cover, 83...S-shaped valve, 83a... Valve body, 83b... Inlet, 83c... Outlet, 83d... Annular groove, 83s... Pivot shaft, 83b... Inlet, 84... S-shaped valve driving means, 84a... Valve driving cylinder, 84b... Valve driving cylinder, 85... Discharge piping, 86... Hopper, 87... Cylinder, 88... Wear plate, 89... Wear ring, 89a... Stepped section, 91... Elastic section, 91a... Recess, 92... Reinforcement section, 92a... Exposed surface, D1... Front-back direction, D2... Left-right direction, D3... Up-down direction

Claims

1. A concrete pipe for transporting ready-mix concrete pumped from a concrete pump, It comprises a pipe body and an annular packing member attached to the connecting end of the pipe body, The packing member comprises an elastic portion made of an elastic material and an annular reinforcing portion that reinforces the elastic portion. The reinforcing portion is a concrete pipe having an exposed surface that forms part of the surface of the packing member and contacts the pipe body.

2. The elastic portion is provided with an annular recess, The concrete piping according to claim 1, wherein the reinforcing portion is arranged in the recess, and the exposed surface is exposed at the opening of the recess.

3. The connecting end of the pipe body is provided with an annular groove that is recessed inward in the axial direction of the pipe body. The concrete piping according to claim 1 or 2, wherein the packing member has a fitting portion that fits into the annular groove.

4. The exposed surface is in contact with the bottom of the annular groove, The concrete pipe according to claim 3, wherein the reinforcing portion extends outward from the exposed surface in the direction of the pipe axis, penetrating the fitting portion.

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