JPH0798301B2 - Internal pipe grinding method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a pipe inner surface inspection method.

2. Description of the Related Art In the manufacturing process of cast iron pipes, after the mortar lining is applied to the inner surface of the pipe, the inner surface is ground with a grindstone such as a grinding wheel or a metal brush to smooth the inner surface of the pipe and to remove impurities on the inner surface of the pipe. There is a grinding process to remove the.

Conventionally, an apparatus shown in FIG. 5 has been used as an apparatus for this grinding step. In FIG. 5, (1) is a cast iron pipe, and a mortar lining layer (not shown) is formed on the inner surface thereof. (2) is a turning roller that rotates the tube (1) around its axis while supporting the tube (1) in the horizontal direction.

(3) is a pipe inner surface grinding device. Here, (4) is an elevating frame, which is supported by an electric jack (5) so that it can be displaced up and down according to the diameter of the pipe (1). A rail (6) is laid on the elevating frame (4), and a carriage (7) is provided on the rail (6) that can move forward and backward in the pipe axis direction toward the end of the pipe (1). .
On the carriage (7, the base end of the horizontal rod (8) is supported by a pin joint (9) so as to be swingable up and down.
This rod (8) is adapted to be inserted into the pipe (1) by the traveling of the carriage (7). A grinding body (10) such as a polishing grindstone or a metal wire is attached to the tip of the rod (8), and the grinding body (10) is mounted on the motor (1) on the carriage (7).
By 1), it is driven to rotate together with the rod (8).

A top guide (12) is provided between the forward end position of the carriage (7) and the pipe end. This Top Guide (12)
Is a frame (13) attached to the lifting frame (4)
And a bearing (14) slidable up and down in the frame (13). The bearing (14) supports the rod body 8) slidably in the axial direction. (15) is a compression spring, and by urging the bearing (14) downward,
The grinding body (10) can be pressed against the inner surface of the bottom of the pipe (1).

In such a structure, when grinding the inner surface of the pipe (1), the rod body (8) is inserted into the pipe (1), and the grinding body (10) receives the force from the compression spring (15). The rod (8) and the grinding body (10) are pressed against the inner surface of the bottom of the pipe (1) by their own weight, and in this state, the pipe (1) and the grinding body (10) are rotated to move the carriage (7). When moving forward and backward,
The inside of the pipe (1) is ground over the entire length and the entire circumference.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention However, in the conventional device as described above, the action point of the force of the compression spring (15) on the rod (8) is relatively changed based on the traveling of the carriage (7). Therefore, the grinding body (10) based on the biasing force of this compression spring (15)
There is a problem that the pressing force to the inner surface of the pipe (1) changes between the pipe end joint and the pipe inner side. That is, for good grinding, it is desirable that the pressing force of the grinding body (10) be uniform over the entire length of the pipe (1). There is a problem that the pressure is larger than the proper value, on the contrary, it is smaller than the proper pressing force on the inner side of the pipe, and the pressing force gradually decreases from the pipe end side toward the inner side.

Therefore, an object of the present invention is to solve such a problem and to make the pressing force by the grinding body a uniform proper value over the entire length of the pipe.

Means for Solving the Problems In order to solve the above problems, the method of the present invention is directed to a horizontal pipe that rotates around an axis at a predetermined position and is capable of advancing and retracting in the pipe axial direction, and a base end portion. And a rod body which is swingably supported up and down on the trolley via the trolley, and which is inserted into the pipe by the traveling of the trolley, and a rotary type which is attached to the tip of the rod and can grind the inner surface of the bottom of the pipe. A grinding body, a bearing that is provided between the forward end position of the trolley and the pipe end and can support the rod by receiving a part of the weight of the rod, and the bearing for urging the bearing in the radial direction. As the grinding body moves between the pipe end and the pipe back side by the traveling of the trolley using the urging means that presses the grinding body against the pipe inner surface, the lever from the bearing to the base end is moved toward the pipe back side. As the arm length becomes shorter, the length of the lever arm from the ground body to the base end becomes longer. On the basis of the above, the first control process of determining that the urging force of the urging means to the bearing is increased toward the inner side of the pipe, and the traveling of the carriage causes the grinding body to move between the pipe end and the inner side of the pipe. As it moves, the distance from the bearing to the grinding body increases toward the inner side of the pipe, and the pressing force of the grinding body due to the weight of the rod increases. The second control process, which is determined to be small, is executed at the same time so that the pressing force of the grinding body becomes a uniform proper value over the entire length of the pipe.

Action According to the method of the present invention, the position of the action point of the force from the bearing to the rod is changed based on the movement of the grinding body in the pipe due to the traveling of the trolley during grinding, and the weight of the rod to the grinding body is changed. The urging force by the urging means is controlled in consideration of both the fact that the acting amount changes and
The pressing force of the grinding body can be uniform over the entire length of the tube.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. Here, the same members as those shown in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 2, a top guide (21) according to the present invention is provided between the forward end position of the carriage (7) and the pipe end, instead of the top guide (12) shown in FIG. .

FIG. 1 shows a detailed structure of the top guide (21). Here, (22) is a frame, which is attached to the lifting frame (4). A bearing (23) is slidably housed in the frame (22),
4) is a guide member for guiding the slide of the bearing (23). A guide bar (25) is fixed to the lower end of the bearing (23), and the guide bar (25) is a cylinder device (26) mounted on the frame (22) as a vertical urging means.
Have been consecutive. An air cylinder is used as the cylinder device (26). A seat (27) through which the guide bar (25) penetrates is formed in the frame (22), and the bearing (23) can be supported on the seat (27) when the bearing (23) descends. Load cell (28) is provided.

An air supply system (29) is connected to the cylinder device (26). The air supply system (29) includes a first air pipe (30) for operating the cylinder device (26) to pull down the bearing (23) toward the load cell (28) and the bearing (23) for the load cell (28). ) And a second air pipe (31) for operating the cylinder device (26) so that the air device is lifted up and lifted from the air pipe (30) (31). Is connected to the air supply source (33). In the middle of the first air pipe (30), a remote control type pressure control valve (3 as a pressure control device for controlling the pressure of the air supplied to the cylinder device (26).
4) is provided.

The frame (22) is provided with a stopper (35) that restricts the upper limit position of the bearing (23) lifted by the cylinder device (26). (36) is a screw body, which is screwed into the frame (22),
5) The position can be changed up and down. (3
7) is a handle for rotating the screw body (36), (3
8) is a rock nut.

Next, the grinding operation of the inner surface of the pipe (1) will be described in detail. Once the tube (1) has been loaded onto the turning roller (2),
The bearing (23) is lifted by the cylinder device (26) so that the grinding body (10) floats from the inner surface of the pipe (1), and the rod body (8) is inserted into the pipe (1) by the forward movement of the carriage (7). To do. When the grinding body (10) is inserted inside the pipe end, the cylinder device (26) pulls down the bearing (23) and the grinding body (10) is placed on the inner surface of the bottom of the pipe (1) as shown in FIG. Press.

When the pipe (1) and the grinding body (10) are rotated in this state and the carriage (7) is moved forward and backward, the inner surface of the pipe (1) is ground over the entire length and the entire circumference.

At this time, if the pulling down force of the bearing (23) by the cylinder device (26) is constant, it becomes the same as the conventional one shown in FIG. 5, and as shown by the fine broken line in FIG. This is not preferable because the pressing force becomes excessively large, the pressing force becomes too small on the inner side of the pipe, and the pressing force decreases from the pipe end toward the inner side of the pipe. Therefore, as shown by the solid line in FIG. 4, the pressure control valve (34) controls the pressing force to a proper constant value over the entire length of the pipe (1). That is, when the grinding body (10) is at the pipe end, the pulling-down force of the bearing (23) is small, and the pulling-down force gradually increases as the grinding body (10) moves toward the pipe inner side.
The pressure control valve (34) is operated to control the pressure of the air supplied to the cylinder device (26).

The pressure of the air supplied to the cylinder device (26), that is, the pressing force applied to the grinding body (10), is the load cell (2
By operating the pressure regulating valve (34) based on the load value of 8), it is properly controlled over the entire length of the pipe (1).
The operation of the pressure regulating valve (34) needs to be performed corresponding to the position of the grinding body (10) in the pipe (1), but the position of the grinding body (10) is the position of the carriage (7). It can be known by detecting the position. Alternatively, dolly (7)
The traveling speed may be kept constant and the pressure control valve (34) may be timer-controlled accordingly.

Next, the pressing force based on the own weight of the rod (8) will be described. In the conventional one shown in FIG. 5, the rod (8) has its base end supported by the carriage (7) and has its tip end grounded (1).
Since it is supported on the inner surface of the pipe (1) via the (0), the grinding body (10) corresponds to half the weight of the rod (8) regardless of the position of the carriage (7). The pressing force always acts. Here, the bearing (23) only functions to apply the force from the compression spring (15) to the rod (8), and does not support the own weight of the rod (8).

However, in FIGS. 1 and 2 based on the present invention, the rod (8) is placed at the position of the top guide (21) via the bearing (23) and the load cell (28) to form the frame (2).
It will be supported by 2). Therefore, the projection of the rod (8) toward the pipe (1) side of the top guide (21) supports the bearing (23) in the top guide (21) and the inner surface of the pipe (1) at two points. To be done. As a result, the pressing force of the grinding body (10) based on the own weight of the rod (8) changes based on the amount of protrusion of the rod (8) from the bearing (23) due to the traveling of the carriage (7). Specifically, as the grinding body (10) advances from the pipe end to the pipe inner side, the amount of protrusion from the bearing (23) in the rod body (8) increases, so that as shown by the coarse broken line in FIG. Along with this, the pressing force also increases.

Therefore, in order to obtain the optimum pressing force as shown in FIG. 4, the grinding body (10) actually moves from the bearing (23) to the rod body (8) by moving in the pipe (1). Considering both the change in the position of the point of action of the force of the force and the change in the weight of the rod (8) acting on the grinding body (10) due to the movement of the grinding body (10). Then, it is necessary to control the pulling down force of the bearing (23) by the cylinder device (26). At this time, as shown by the double-dashed lines in FIG. 4, the change in the pressing force due to the own weight of the rod (8) is due to the change in the point of action of the force from the bearing (23) to the rod (8). Since it is smaller than the change (usually less than half), basically there is no change in increasing the pull-down force of the bearing (23) from the pipe end toward the pipe inner side.

When the grinding of the inner surface of the pipe (1) is completed, the bearing (23) is lifted by the cylinder device (26) and applied to the stopper (35) to lift the grinding body (10) from the inner surface of the pipe (1). Next, the carriage (7) is retracted to pull out the rod (8) from the pipe (1), and then the pipe (1) is carried out from the turning roller (2).

EFFECTS OF THE INVENTION As described above, according to the present invention, the position of the action point of the force from the bearing to the rod is changed, and the weight of the rod itself is changed based on the movement of the trolley during grinding in the pipe. In consideration of both of the fact that the amount acting on the grinding body is changed, the urging force by the urging means is controlled,
When grinding the inner surface of the pipe, the pressing force of the grinding body acting on the inner surface of the pipe can be controlled to an optimum constant value over the entire length of the pipe.

[Brief description of drawings]

FIG. 1 is a detailed view of an essential part of an embodiment of the present invention, FIG. 2 is an overall view thereof, FIG. 3 is a sectional view of the essential part thereof, FIG. 4 is a characteristic diagram of its pressing force, and FIG. The figure is an overall view of a conventional example. (1) …… pipe, (7) …… carriage, (8) …… rod, (1
0) …… Grinding body, (23) …… Bearing, (26) …… Cylinder device (biasing means), (34) …… Pressure adjusting valve (pressure adjusting device)

Claims (1)

[Claims] 1. A trolley which is capable of advancing and retracting in the axial direction of a pipe which rotates in a horizontal direction around a shaft at a predetermined position, and which is supported on the trolley via a base end portion so as to be vertically swingable. At the same time, the rod body inserted into the pipe by the traveling of the carriage, the rotary grinding body attached to the tip of the rod and capable of grinding the inner surface of the bottom of the pipe, and the forward end position and the pipe end of the carriage. Using a bearing that is provided between the bearings and can support the rod by receiving a part of the weight of the rod, and a biasing means that biases the bearing in the radial direction to press the grinding body against the inner surface of the pipe. , As the grinding body moves between the pipe end and the pipe back side by the traveling of the trolley, the length of the lever arm from the bearing to the base end portion becomes shorter toward the pipe back side, and from the grinding body to the base end portion. Based on the increase in the length of the lever arm, the urging force on the bearing by the urging means is increased. The first control process that decides to increase the depth toward the pipe back side, and as the grinding body moves between the pipe end and the pipe back side due to the traveling of the truck, the distance from the bearing to the grinding body increases toward the pipe back side. On the basis of the increase in the pressing force of the grinding body due to the self-weight of the rod, the second control process for determining that the urging force of the urging means to the bearing is made smaller toward the inner side of the pipe is simultaneously executed. Then, the method for grinding a pipe inner surface is characterized in that the pressing force of the grinding body is set to a uniform proper value over the entire length of the pipe.