JPH0439434Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention is a squeeze pump that establishes the durability and operational safety of the pumping tube used in squeeze-type pump trucks for transferring and placing ready-mixed concrete. This relates to a type pumping tube.

[Conventional technology]

Conventionally, squeeze-type pumping tubes press a curved tube along the inner surface of the pump case with a roller rotating around a rotating shaft, and by repeating the tube's restoring action, the tube is compressed into ready-mixed concrete. It is used under severe conditions in which it takes in and discharges water, and the inner rubber is therefore severely worn or damaged. In general, a pumping tube has a structure in which abrasion-resistant rubber is placed on the inner surface, a reinforcing layer is provided on the outside for the purpose of pressure resistance and elongation resistance, and a jacket rubber is placed on the outermost side. As mentioned above, since it is subject to severe wear and damage, the sensing method for detecting the condition is
Disclosed in the issue. These methods involve embedding a conductor over the entire length or part of the pumping tube, and determining the difference in electrical conductivity between the conductors or between the connecting fittings between the conductor and the pumping tube.

These methods detect when a conductor is cut by a solid object in the fluid, or detect when a buried conductor comes into contact with the fluid by using the electrical conductivity of the fluid itself. It was hot. However, the conductor is partially inserted,
It is something that cannot fully demonstrate its sensing ability. In particular, the conductor cannot achieve its purpose unless it is provided immediately outside the inner rubber.
In addition, the sensing ability cannot be demonstrated unless the entire length and circumference are set.

[The problem that the idea aims to solve]

The configuration of the conductor in the conventional pumping tube is such that the conductor is buried in a layer other than the reinforcing layer. Therefore, it has the following problems.

That is, the pumping tube is subjected to repeated severe pressure contact force and stretching action, and therefore requires a large pressure contact force and high tension resistance. Therefore, sufficient reinforcing layers in the radial and axial directions to support the pressure contact force and the stretching force are embedded within the wall thickness of the limited dimension that is curved and accommodated on the inner surface of the pump case.

Therefore, if a conductor is buried separately in a layer other than the reinforcing layer, if the conductor is placed under the reinforcing layer (outside the inner rubber), it will dig into the inner rubber and cause damage to that part. The inner rubber becomes thinner, and the wear life itself is reduced. Similarly, if the buried conductor is buried at a higher density,
Things that not only lack stability, such as inhibiting adhesion with the rubber part, variation in dimensions, increase in weight, change in pressurizing characteristics as a pumping tube, and increase and variation in pressing load, but also cause cost increases. Naturally, there were limitations, and only rough burial was possible. Therefore, the wear detection density is also low, and there is a drawback that the ability to detect partial damage caused by sharp solid objects in the fluid that sometimes occurs is poor.

In addition, since the pumping tube undergoes repeated large bending and restoring due to buckling, when the buried conductor is placed at a different attachment angle from the main reinforcing layer,
The pumping tube itself becomes difficult to bend. On the other hand, if the angle is set larger than that of the main reinforcing layer, the buried conductor will suffer from severe bending fatigue, resulting in premature breakage.

As described above, burying an extra conductor in addition to the necessary reinforcing layer not only increases the burying cost but also causes a decrease in the performance and durability of the pumping tube.

Therefore, it is necessary to solve the problem of a structure that avoids conductors other than the reinforcing layer.

[Means to solve the problem]

In order to solve the above problems, it is necessary to minimize the thickness of the reinforcing layer, have a high-density sensing ability to detect partial damage to the inner surface rubber, and maintain sufficient reinforcing properties. It is essential.

In the first place, as shown in the outline diagram of concrete pumping operation in Figure 1, the pumping tube is inscribed in a curved shape inside the case 2 of the squeeze pump, and the suction side is connected to the hopper that supplies ready-mixed concrete, and the discharge side is It is connected to the discharge side piping that transports the concrete to the concrete placement site, and the rotation of the rotor 5 and roller 6 squeezes out the fresh concrete, moving the fresh concrete from point to point.
It is pushed out in sequence from one point to another, and by repeating this process a pumping action is achieved.

Therefore, conventional reinforcements have mainly been made of fiber reinforcement, and there are also composite reinforcements made of metal and fiber materials, but in this case, the metal material is wrapped in fiber material. It is. Therefore, in the present invention, the reinforcing layer is composed of continuous filaments over the entire length, and is made of steel, which has excellent elongation resistance and pressure resistance with a minimum number of plies, and has strong primary adhesion to rubber. This research explores the possibility of solving the problems of the conventional method by embedding cords in rubber in a cross-shaped manner to form a reinforcing layer.

That is, as shown in the enlarged cross-sectional view of the pumping tube according to the present invention in FIG. It is constructed by forming a reinforcing layer 8 and covering the outside thereof with an outer surface rubber 9. Note that various elastomers are appropriately selected and used as the elastic body such as rubber.

Therefore, when the inner rubber is worn out or damaged, there is a steel cord inside it that runs the entire length and circumference.
Since it is densely formed, it is capable of detecting even the slightest partial damage to the inner rubber. The sensing means are steel cord and hopper,
An electrical sensing device for detecting current value or potential difference is set between the terminals and the discharge side piping.
In addition, the reinforcing layer is only two layers with a crossed structure of high-strength steel cords, and the area occupied by the reinforcing layer within the wall thickness is also minimized, so that within a certain wall thickness,
Not only can the area occupied by the rubber be maximized, but the pumping tube has a structure with excellent pressure resistance, flexibility, and bendability. The sensing device will be described in detail in Examples based on the drawings.

[Effect]

In particular, the pumping tube with the above structure has only a reinforcing layer with a cross structure of steel cords, so compared to conventional reinforcing layers, the area occupied by the reinforcing layer is minimized, and it has suitable pressure resistance and elongation resistance. In addition, it has a good bending effect. In addition, since the reinforcing layer is made of highly conductive steel cord, the entire length and circumference are densely constructed, so if an electrical sensing device is installed, the inner rubber will
It can immediately detect even the slightest partial damage.

〔Example〕

Next, reference will be made to an example of an electrical sensing device.

FIG. 3 is an explanatory diagram of the connection terminal configuration. For the purpose of explanation, the cap 11 inserted into the hose is used as a connection body for the terminal A. This corresponds to 4.

In the figure, 1 is a pumping tube, 7 is an inner rubber, 8 is a steel cord reinforcing layer, 9 is an outer rubber, 10 is fresh concrete, and 11 is a base.

Therefore, when connecting the terminal, if terminal A is connected to the hopper 3 or the discharge pipe 4 itself, and terminal B is connected to the steel cord reinforcing layer 8 provided along the entire length and circumference of the pumping tube 1, then the terminal A
When is the hopper 3, the terminal B connects to the steel cord reinforcement layer 8 of the pumping tube located close to the discharge side. Further, when the terminal A is the discharge side pipe 4, the terminal B is connected to the steel cord reinforcing layer 8 of the pumping tube located near the hopper 3. If the terminals in this case of opposite positions are designated as A' and B', all four points may be connected as A-B and A'-B'.

FIG. 4 is an example of an electrical sensing device, with terminal A
A power source 13 and a lamp 12 are provided between the terminal A and the terminal B. When the terminal A is connected to the hopper 3 and the terminal B is connected to the steel cord reinforcing layer 8 of the pumping tube located near the discharge side, the electrical conductivity The electrical circuit is cut off by the bad inner rubber. Therefore, when the inner rubber is worn away by the fresh concrete or damaged by sharp aggregates and the steel cord comes into contact with the fresh concrete, electricity will be applied through the fresh concrete and the lamp 12 will turn on. The light comes on and damage to the inner rubber is detected.

[Effect of idea]

The present invention has the structure described above, and can minimize the thickness of the reinforcing layer compared to the conventional method using many reinforcing layers, and can increase the durability by increasing the thickness of the inner rubber. In addition, all the reinforcement layers have a sensing function and have a sharp sensing ability, which prevents the risk of work interruption due to hose damage during concrete pouring, and also ensures that the causes of damage can be prevented beforehand. By sensing this, it is now possible to reliably know when to replace the pumping tube without wasting any waste. In addition, when the conventional method was to actually measure the average lifespan of a pumping tube and replace it when it approached that value, the usage period was at least 20% shorter, but it can be used until the maximum lifespan. It became possible to do so.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of the fresh concrete pumping operation of the pumping tube, Fig. 2 is an enlarged sectional view of the pumping tube of the present invention, Fig. 3 is an explanatory diagram of the connection terminal configuration, and Fig. 4 is an electrical sensing It is an example figure of a device. 1...Pumping tube, 2...Pump case, 3...Hopper, 4...Discharge side piping, 8...
Steel cord reinforcement layer.

Claims (1)

[Scope of utility model registration request] In the pumping tube that sucks in and discharges fresh concrete fluid through the squeezing action and restoring action that curve along the inner surface of the case of the squeeze pump, material for pressure resistance and restoring reinforcement is applied to the outside of the elastomer inner layer over the entire length and circumference of the pumping tube. As a reinforcing layer, a steel cord with a cross composition of the bias cord is used, the A terminal is connected to the discharge side piping or/and the suction side hopper, and the B terminal is connected to the reinforcing steel cord near the opposite side of the A terminal position. Squeeze type pumping tube with a sensing function in all reinforcement layers equipped with a target sensing device.