JPS6315969B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an apparatus for quenching a heated steel pipe by immersing it in cooling water in a water tank. Relating to a regulating device.

One of the methods to make steel pipes high in tension and toughness is to use quenching and tempering, just like other steel products. BACKGROUND ART Conventionally, as a method of quenching steel pipes, a method of quenching a heated steel pipe by immersing it in water has been known. However, if the entire steel pipe is simply immersed in cooling water, the surface of the steel pipe will be covered with a vapor film created by the boiling of the cooling water, and the cooling rate of the pipe will be lower than the critical cooling rate for martensitic transformation required for normal quenching. However, the hardening effect is no longer obtained. In order to remove this steam film, high pressure water is injected onto the inner and outer surfaces of the steel pipe. Also, in order to prevent uneven heating, a method is used in which the steel pipe is rotated underwater. In this type of immersion hardening method, heated steel pipes are normally thrown into the cooling water of a water tank from the air, but in order to achieve more uniform hardening, the steel pipes are lowered and immersed while rotating before being immersed. The device for holding and rotating the steel pipe becomes complicated. Furthermore, as the steel pipe descends into the water, the inner cooling nozzle also needs to be moved, which poses a problem in that alignment of the steel pipe and the inner cooling nozzle is difficult and time consuming. To solve this problem, a heated steel pipe is held at an appropriate depth in a water tank, and the water level of the cooling water in the tank is raised while the steel pipe is rotated to perform immersion and quenching. One possible method is to lower the water level and take out the steel pipe later. In this case, the steel pipe rotation drive device can be fixedly installed in the water tank, and the inner cooling nozzle can be easily aligned, but it is difficult to quickly raise and lower the water level of the cooling water in the water tank using normal water injection and drainage methods. This is difficult, and there are problems such as the need for large-scale water supply and drainage equipment.

The present invention has been made in order to solve the various problems mentioned above, and it is an object of the present invention to provide a water level adjustment device for a steel pipe immersion hardening apparatus that can easily change the water level of a water tank for hardening in a short time. purpose.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic cross-sectional view of a steel pipe immersion hardening apparatus equipped with a water level adjusting device of the present invention. Note that this figure is a cut along a plane perpendicular to the longitudinal direction of the steel pipe set for hardening. A set of rotary rollers 9 is rotatably supported on a bearing stand 10 in the quenching water tank 11 . This rotating roller 9
A plurality of rotary rollers 9 are arranged at appropriate intervals in the longitudinal direction in the water tank 11, and the shafts 9a of the rotary rollers 9 are connected to a drive device (not shown) and driven to rotate, whereby the rotary rollers 9 are rotated at the same position. .

A base 5 is provided on the side of the quenching water tank 11, and pillars 4 are erected on the left and right sides of the base, and a water tank 2 is arranged on the base 5 inside the pillar 4. A cylinder device 12 is provided on the base at the outer position of 4. A pulley 8 is pivotally supported on the upper end of the column 4, and one end of a lifting chain 7 is attached to the upper end of the water tank 2, and the other end of the lifting chain 7 is connected to a cylinder device from the water tank 2 via the pulley 8. It is fixed to the piston rod 13 of 12. In this way, the water storage tank 2 on the base is configured to be able to be lifted up from the cylinder device 12 by the chain 7 via the pulley 8. Wheels 6 are attached to the left and right sides of the water tank 2. Due to the bias of the cylinder device 12, the water tank 2 rises via the chain 7, but at this time, the wheels 6 on the sides of the water tank slide in contact with the inner sides of the left and right columns 4, thereby causing the water tank 2 to move up. 2 stably rises or falls along the support column 4.

As a whole, the bottom of the quenching water tank 11 and the bottom of the water storage tank 2 are connected by a pipe 3, and an extendable sliding double pipe 14 is attached to the bottom of the water storage tank 2. The lower end of the heavy pipe 14 is connected to the end of the pipe 3 on the water tank side.
That is, for example, the outer pipe of the double pipe 14 is fixed to the bottom of the water tank 2, and the inner pipe is fixed to the end of the pipe 3, so that when the water tank 2 moves up and down, the outer pipe of the double pipe 14 moves up and down. , the inner tubes are adapted to slide over each other. A suitable sealing member is provided between the outer pipe and the inner pipe of the double pipe 14, and the water storage tank 2
Also, the water in the pipe 3 is prevented from leaking. Compared to the horizontal or vertical cross section of the water tank 2,
The cross section of the double pipe 14 is sufficiently small. Therefore, as the water tank 2 is raised or lowered by the cylinder device 12, the water level of the cooling water in the quenching water tank 11 is lowered or raised.

One embodiment of quenching a steel pipe using an immersion quenching apparatus equipped with a water level adjusting device having such a configuration will be described. The steel pipe heated in the heating furnace is carried on rotating rollers 9 in water tank 11 by a suitable conveying device. At the same time, the rotating roller 9 rotates, thereby rotating the heating steel pipe 1. At this time, the water tank 2 is at the solid line in the figure, that is, the bottom of the water tank is in contact with the base 5, and the water tank 11 for quenching is in contact with the base 5. The water level of the cooling water inside is low and the cooling water is not in contact with the steel pipe 1 on the rotating roller 9. After this, the cylinder device 12 is activated and the water tank 2 rises, and when it comes to the position shown by the broken line in the figure,
The water level in the water storage tank 2 decreases due to the water head difference, and the water level of the cooling water in the quenching water tank 11 increases accordingly.
The steel pipe 1 on the rotating roller 9 is completely immersed. A broken line 20 of the quenching water tank 11 in the figure represents the rising water level at this time. At the same time as the water level in the water tank 11 rises, high-pressure cooling water is injected from an inner surface cooling nozzle (not shown) to harden the inner and outer surfaces of the tube (the outer surface nozzle is not shown). After quenching is completed, the water tank 2 is lowered again, the water level in the quenching water tank 11 is lowered, and the quenched steel pipe 1 is exposed from the water surface. Here, the hardened steel pipe 1 is carried out of the tank, and the next steel pipe 1 to be hardened is placed on the rotating rollers 9 in the water tank 11. Incidentally, since a considerable amount of power is required to move the water tank 2 up and down, the power of the driving source of the cylinder device can be reduced by attaching a counterweight 15 to the water tank 2 as shown in FIG. In the above-described embodiment, the steel pipe does not move in the water tank during quenching, so positioning the inner surface cooling nozzle is easy, and the rotating rollers that support and rotate the steel pipe 1 are also fixedly installed, so the rotation drive mechanism is simple. Simplified. Compared to when water is supplied into the aquarium from above, the movement of waves on the water surface is quieter, the aquarium itself can be made more compact, and the overall water volume remains essentially the same, and only the amount lost due to evaporation is replenished as needed. Just do it.

The above description is one embodiment of the present invention, and
The present invention can be implemented in various embodiments other than those described above. For example, the vertical drive mechanism for the water tank 2 may be configured in the form of a so-called hoisting device by attaching a drive motor to the shaft of the pulley 8 instead of using the cylinder device as shown. Furthermore, the device of the present invention is not limited to a quenching device that immerses steel pipes as the water level rises.
The present invention can be similarly applied to a case where the water level is adjusted by changing the size of the steel pipe in a quenching device that rotates the steel pipe and immerses it in water in a water tank.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view of a water level adjusting device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing another embodiment of the present invention. 1...Steel pipe, 2...Water tank, 3...Pipe, 4
... Support column, 5 ... Base, 6 ... Wheel, 7 ... Lifting chain, 8 ... Pulley, 9 ... Rotating roller, 11
... Quenching water tank, 12 ... Cylinder device, 14 ...
...Double pipe (expandable pipe), 15...Counterweight.

Claims (1)

[Claims] 1. A rotating roller is arranged in a water tank for quenching, a heated steel pipe is supported and rotated on the rotating roller, and the steel pipe is immersed in cooling water in the water tank for quenching to perform quenching. In the steel pipe immersion quenching apparatus, a water tank that can move up and down with respect to the quenching water tank is provided, and both water tanks are connected through a pipe, and the water level of the quenching water tank is adjusted by driving the water tank up and down. A water level adjustment device for a steel pipe immersion quenching device, which is characterized by changing: 2. The water tank has wheels in contact with the pillars on its sides, and has a telescopic tube connected to the pipe at its bottom, is suspended by a drive chain via a pulley on the pillars, and is suspended by a drive chain on the pillars. Claim 1, characterized in that a counterweight is attached to the water tank, and the water level of the cooling water in the quenching water tank is raised to immerse the heated steel pipe on the rotating roller. A water level adjustment device for the steel pipe immersion quenching equipment described above.