JPH0519581Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention is used in the parts of the swinging pipe that are most likely to wear out in a swinging type pump that transports earth and sand, ready-mixed concrete, etc., thereby extending the life of the swinging pipe. This invention relates to a valve device for a concrete pump for achieving this.

[Prior art] A pump for transporting earth, sand, ready-mixed concrete, etc. has a swing pipe located inside the hopper that alternately communicates with two transport cylinders outside the hopper, and the transported material discharged from the transport cylinders is connected alternately to two transport cylinders outside the hopper. There is an oscillating pump designed to force-feed water through the oscillating tube.

To explain the case of a concrete pump as an example, the valve device of the swing type concrete pump has two suction and discharge ports 2 arranged side by side on the lower front side wall of the concrete hopper 1, as shown in FIGS. 3 and 4. A valve plate 3 having holes corresponding to both the suction and discharge ports 2 is attached to the inner surface, and two transport cylinders 4 and 5 are installed on the lower front surface of the hopper 1 in correspondence with the two suction and discharge ports 2. Connecting. Inside the concrete hopper 1 above,
A swinging tube 7 whose one end is connected to the transport pipe 6 outside the hopper 1 is positioned so that the opening at the other end of the swinging tube 7 is 2.
It is configured to be swingable so as to communicate alternately with two transport cylinders 4 and 5 through two suction and discharge ports 2, and a connecting plate 9 is attached to a swing shaft 8 which is rotatably supported by the concrete hopper 1. Due to the alternate reciprocation of the pinions inside the transport cylinders 4 and 5 and the left-right rocking of the rocking tube 7 by the rocking shaft 8, the concrete 10 in the concrete hopper 1 is moved from the suction and discharge port 2. When being sucked into one transport cylinder, the concrete previously sucked into the other transport cylinder is discharged through the swing tube 7.

Since the swing tube 7 swings in the left-right direction around the swing axis x, the swing tube 7 and the valve plate 3
The sliding parts are prone to wear. When this sliding part wears out, the sealing performance is impaired and the pressure inside the transport cylinders 4, 5 escapes, making it impossible to forcefully transport the concrete through the swing pipe 7.

Therefore, conventionally, a valve ring 1 made of a wear-resistant material is attached to the open end of the swing tube 7 inside the hopper 1.
1 is attached so that the front surface of the valve ring 11 slides on the valve plate 3 so that the sealing performance is not impaired. Also, valve ring 11
In order to make it easier to pass through the aggregate (stone) contained in the concrete 10 when the valve plate 3 contacts the valve plate 3 and slides in the left-right direction, an angle θ (30 to 45 degrees) is formed on the outer periphery as shown in FIG. ) is chamfered.

[Problems to be solved by the invention] However, since the conventional valve ring 11 is chamfered at an angle θ on the outer periphery as described above, the aggregate 12 contained in the concrete 10 is When the valve ring 11 is bitten at the end of the stroke as shown in FIG. It may disappear. If the swing tube 7 is not switched, a component of the driving force will act in the axial direction of the swing tube 7, potentially deforming the swing tube 7. This tendency became more noticeable as the proportion of aggregate 12 contained in concrete 10 increased.

Therefore, the present invention aims at crushing the aggregate with a large force when the aggregate is caught between the outer periphery of the valve ring and the hole in the valve plate while the swinging tube is swinging. The purpose is to improve the switching performance of the switch.

[Means for Solving the Problems] The present invention includes a pump that forces the transported object drawn into the transport cylinder through the swing pipe, and a valve ring is fitted to the end of the swing pipe on the transport cylinder side.
The outer periphery of the valve ring on the sealing surface side is tapered with a large diameter, and a protruding portion with a sharp tip is directed inward at the edge of the suction and discharge port of the valve plate at the stroke end portion of the swing tube. This invention relates to a valve device for a concrete pump, which is characterized in that it is provided with a valve device.

[Function] When the valve ring reaches near the stroke end due to the swinging of the swing pipe and bites into aggregate, the outer periphery of the valve ring tapers in the opposite direction to the chamfer angle of conventional valve rings. Because of the curved shape, a large crushing force can be obtained, and the shearing effect is enhanced by providing an inwardly pointed overhang on the edge of the intake and discharge port of the valve plate at the stroke end of the swing tube. It is possible to crush the entrapped aggregates and the like. This avoids the inability to switch the swing tube.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

1 and 2 show an embodiment of the present invention, in which a conventional chamfer is applied to the outer periphery of a valve ring 11 that is attached to the open end of the swing tube 7 in the hopper 1 and brought into contact with the valve plate 3. The valve ring 11 is tapered in the opposite direction, and has a cross-sectional shape that widens toward the end so that the contact surface with the valve plate 3 expands, so that the outer periphery of the valve ring 11 forms an acute angle. Furthermore, an inward projecting portion 14 is provided on the edge of the suction/discharge port 2 of the valve plate 3 at the stroke end portion of the swing tube 7, and the tip of the projecting portion 14 is sharpened to meet the taper portion 13 of the valve ring 11. Aggregate 1 between
Make it possible to crush 2. Other configurations are the 4th
The structure is the same as that of the conventional example shown in FIGS.

When the swing tube 7 is swung left and right when sucking and discharging concrete, the valve ring 11 slides in contact with the valve plate 3, and the two suction and discharge ports 2 are alternately switched to the suction side and the discharge side.

When the valve ring 11 bites into the aggregate 12 contained in the concrete 10 at the stroke end as shown in FIG. As a result, the crushing force against the aggregate 12 increases and acts on the aggregate 12, and together with the reverse tapered shape of the valve ring 11, the aggregate 12 is easily crushed.
Thereby, the swing tube 7 can be reliably switched.

The crushing force against the aggregate 12 is large because
In the case of a conventional valve ring whose outer periphery is chamfered at an angle θ, when the driving force in the operating direction of the swing tube 7 is QKg, the crushing force of Qsinθ is as shown in Fig. 5.
2, whereas in the present invention, the shape of the valve ring 11 is tapered opposite to the chamfering direction of the conventional system, so if the driving force Q of the swing tube 7 is constant, Q>Qsinθ. Because it will be.

Moreover, in the present invention, the edge of the suction/discharge port 2 of the valve plate 3 at the stroke end portion of the swing tube 7 is provided with a projecting portion 14 with a pointed tip facing inward, so that the taper 13 of the valve ring 11 The shearing effect by the and overhanging portion 14 is enhanced, and it becomes possible to crush the aggregate 12 sandwiched between the taper 13 and the overhanging portion 14 more easily.

In addition, although the above-mentioned example showed the case where concrete was targeted as an object to be transported, it is not limited to a concrete pump.

[Effects of the invention] As described above, according to the concrete pump valve device of the present invention, the outer periphery of the valve ring is tapered to expand outward, and the valve plate at the stroke end of the swing pipe is tapered. Since the edge of the suction/discharge port has a structure in which an overhang with a sharp tip faces inward, even when the valve ring gets caught in the aggregate contained in the transported object, the aggregate is crushed with a large crushing force. It is possible to prevent the situation where the swing tube cannot be switched due to the possibility of crushing the
Reliability can be increased.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the main parts of an embodiment of the valve device of the present invention, Figure 2 is an explanatory diagram showing the state in which the valve ring shown in Figure 1 is biting aggregate, and Figure 3 is a diagram of a concrete pump. Sectional view showing the flow path switching valve, No. 4
The figure is a view taken along the - arrow in FIG. 3, and FIG. 5 is a diagram showing the crushing force when a conventional valve ring operates. 1 is concrete hopper, 2 is suction and discharge port,
3 is a valve plate, 4 and 5 are transportation cylinders, 7
is a rocking tube, 11 is a valve ring, 12 is an aggregate, 1
3 indicates a taper, and 14 indicates an overhanging portion.

Claims (1)

[Scope of utility model registration request] A valve ring is fitted to the end of the swinging tube on the transport cylinder side of the pump for pumping the transported material sucked into the transport cylinder through the swinging pipe, and the outer periphery on the sealing surface side of the valve ring is tapered with a large diameter. A valve device for a concrete pump, further comprising: a protruding portion with a pointed tip directed inward at the edge of the suction/discharge port of the valve plate at the stroke end portion of the swing pipe.