JPS59100220A - Immersion hardening device of steel pipe - Google Patents

Abstract

PURPOSE:To perform efficiently immersion hardening of a steel pipe by holding the heated steel pipe in a suitable position in a water tank, raising the level of cooling water while rotating the steel pipe to immerse and harden the pipe then lowering the level and removing the steel pipe. CONSTITUTION:A titled device has an inclined guide 25 which is formed with a slope continuous from the upper part of a water tank 11 for hardening to the position of the revolving roll 9 in the water tank, an endless turning device 26 which has three dogs 29-31 spaced from each other on the outside surface, the 1st arm 19, 2nd arm 29 and a steel pipe scooping arm 21 which drop the steel pipe 1 on a conveyance roll 2 into the space between the dogs 29, 30, 31 of the device 26 and the guide 25 by moving upward, forward, downward and backward in a rectangular shape, and a press roll 34 which is provided above the roll 9 and moves vertically with respect to the roll 9. A level adjustment device which adjusts upward and downward the water level in the tank 11 is further provided.

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, which can uniformly quench the inner and outer surfaces of the steel pipe and prevents damage or bending on the outer surface of the steel pipe. This invention relates to steel pipe immersion hardening equipment.

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 reach the critical cooling rate required for martensitic transformation, which is necessary for normal quenching. The hardening effect will no longer be obtained. In order to remove this 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 quenching method, the energized steel pipe is usually heated from the air by cooling water in a water tank.

However, in order to achieve more uniform quenching, the steel pipe is lowered and dipped while rotating before it is dipped, which makes the device for holding and rotating the steel pipe complicated. Furthermore, as the steel pipe descends into the water, the inner surface cooling nozzle must also be moved, which poses a problem in that alignment of the steel pipe and the inner surface cooling nozzle is troublesome 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, it is possible to fixedly install the lead pipe rotating thickening device inside the water tank, and the positioning of the internal cooling nozzle is easy.
There are problems such as it is difficult to lower it and the water supply and drainage equipment must be large-scale.

The present invention was made to solve the above-mentioned quality problems, and it is possible to uniformly harden the inner and outer surfaces of a steel pipe,
Another object of the present invention is to provide a steel pipe immersion quenching apparatus that can easily change the water level of a quenching water tank in a short time.

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

FIG. 1 is a schematic cross-sectional view of the steel pipe immersion hardening apparatus of the present invention. Note that this figure was cut along a plane perpendicular to the longitudinal direction of the steel pipe set for hardening.

A set of rotating rollers 9 is arranged in the quenching water tank 111. A plurality of rotating rollers 9 are disposed in the quenching water tank 11 at appropriate intervals in the longitudinal direction, and are connected to a drive device (not shown) and driven to rotate.

A base 16 is provided on the side of the quenching water tank 11, and an L-shaped support 17 is erected on the base. Further, on the base 16 inside the support column 17, a carrying device, which will be described later, is installed. Further, inside the support column 17, a plurality of conveyance rollers 2 are distributed along the conveyance line of the steel pipe 1. 18 is a drive device for the conveyance roller 2.

In the steel pipe loading device, the first and second arms 19 and 20 are connected to the base 1.
It is pivoted at a fixed point on 6. The tip of the first arm 19 is pivotally supported by the rear part of the steel pipe scooping arm 21, and the second arm 20 is connected to the front part 21a of the steel pipe scooping arm 21 via a link 22. The upper surface of the front end of the steel pipe scooping arm 21 is recessed in a substantially V-shape. The other ends of the first and second arms are pivotally connected to piston rods of separate cylinder devices 23, 24, respectively, installed horizontally on the base 16.

An endless rotation device 26 is installed above the quenching tank 11, in which an inclined guide 25 is arranged from near the conveyance roller 2 to a position near the rotary roller 9 in the quenching tank 11. In this endless rotation installation, the endless chain 28 is wound around a pair of sprockets that are pivotally supported by the frame 27, and the endless chain 28 is rotated in the direction of the arrow in the figure as the sprockets rotate. A plurality of dogs 29, 30, 31, three in the illustrated embodiment, are fixed to the outer surface of the endless chain 28 at appropriate intervals. The tips of each dog 29, 30, 31 are bent in the same direction so that the steel pipe 1 on the rotating roller 9 can be fed onto the underwater skid 32 as will be described later.

A cylinder device 33 for driving the holding roller is attached to the tip of the support column 17 at a position vertically above the rotating roller 9. A presser roller 34 is attached to the tip of the piston rod of this presser roller driving cylinder device 33.

In such a configuration, when the heated steel pipe 1 is conveyed by the conveyor rollers 2 and stopped at the position of the quenching device, the conveying device first transfers the heated steel pipe 1 to the cylinder device 24 of the second arm 20.
is activated and its piston rod extends (solid line arrow), and the second arm 20 accordingly rotates clockwise (solid line arrow direction), and the tip of the scooping arm 21 touches the first arm 1.
Diagonally upward from the tip of 9 (in the direction of solid arrow 35)
Rotate to (upper layer). FIG. 1 shows the state at this time. As a result, the heated steel pipe 1 on the conveying roller 2 is scooped from the conveying roller 2 onto the scooping arm 21. Next, the cylinder device 23 of the first arm 19 is actuated to contract its piston rod, and accordingly, the first arm 19 rotates counterclockwise (in the direction of the solid line arrow), and the scooping arm 21
moves (advances) in the direction shown by the solid line arrow 36. Next, when the piston rod of the cylinder device 24 of the second arm 20 is retracted, the second arm 20 reversely rotates in the direction of the dashed arrow, so that the tip of the scooping arm 21 moves past the tip of the first arm. It rotates (descends) diagonally downward (in the direction of the broken line arrow 37) about the center. At this time, the steel pipe on the scooping arm 21 is dropped into the waiting dog 29 of the endless rotating device 26 and the inclined guide 25. Then the first arm 19
The piston rod of the cylinder device 23 extends, the first arm rotates in the direction of the broken line arrow, and the scooping arm 21 moves backward (retreats) as indicated by the broken line and returns to its original position. In this manner, the distal end of the scooping arm of the carry-in device repeats a substantially rectangular movement of rising, advancing, descending, and retreating.

Steel pipe 1 locked between dog 29 and inclined guide 25
The rotating roller 9 in the aquarium 11 rolls on the slope of the inclined guide 25 due to the rotation of the endless chain 28 without any impact.
be placed on top. At this time, at the same time, the hardened steel pipe 1 jumps out from the rotary roller 9 in front of the dog 29 and is taken out of the tank from the bottom of the underwater skid 32 (which is always immersed in water) by the delivery device 38. After the steel pipe 1 is placed on the rotating roller 9, the presser roller drive cylinder device 33 is activated, the presser roller 34 is lowered, and the steel pipe 1 is pressed against the rotating roller 9. At the same time, the rotating rollers 9 are rotationally driven, and the steel pipe 1 is rotated by the frictional force thereof. During the rotation of this steel pipe, the water level of the cooling water at the position 40 rises, and the steel pipe 1 is immersed. At the same time as this immersion, an inner cooling water nozzle ( High-pressure water is injected onto the inner surface of the steel pipe from a water tank (not shown), and high-pressure water is also injected onto the outer surface of the pipe from an outer header 41 installed in the water tank, thereby simultaneously quenching the inner and outer surfaces of the steel pipe. Note that the inner surface cooling nozzle cools the inner surface of the tube and removes air from the tube during immersion, and the outer header cools the outer surface of the tube and stirs water.

Next, the water level adjusting device of the present invention for raising and lowering the water level of the cooling water will be explained with reference to FIG.

Another 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 this base.

A water tank 10 is arranged on the base 5 inside the column 4, and a cylinder device 12 is provided on the base at a position outside the column 4. A pulley 8 is pivotally supported at the upper end of the column 4.

One end of a drive chain 7 is attached to the upper end of the water tank 10, and the other end of the drive chain is fixed to the piston rod 13 of the cylinder device 12 from the water tank 10 via a pulley 8. In this way, the water tank 10 on the base is configured to be able to be lifted 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 10. Due to the bias of the cylinder device 12, the water tank 10 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, and as a result, the water tank 10 rises. Stably ascends or descends along the pillar 4.

As a whole, part 2 of the quenching water tank 11 and the bottom of the water storage tank 10 are connected by a pipe 3.
An expandable telescoping double pipe 14 is attached to the bottom of the pipe 1, and the lower end of the double 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 10, and the inner pipe is fixed to the end of the pipe 3, so that when the water tank 10 moves up and down, the outer pipe of the double pipe 14 moves up and down. , the inner tubes are adapted to slide relative to each other. A suitable sealing member is provided between the outer pipe and the inner pipe of the double pipe 14 to prevent the water in the water tank 10 and the pipe 3 from overflowing. Water tank 1
The cross section of the double pipe 14 is sufficiently small compared to the horizontal or vertical cross section of the double pipe 14. Therefore, as the water tank 10 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.

According to the present invention, since the steel pipe does not move within the water tank during quenching, positioning of the inner surface cooling nozzle is easy, and the steel pipe 1
Since the rotating roller that supports and rotates the image is also fixedly installed, its rotational drive mechanism is simplified. The water level rises and falls faster than when water is supplied into the tank from above.
Further, essentially, the total amount of water does not change, and only the amount reduced due to evaporation etc. needs to be replenished as appropriate. In order to control the water temperature, fresh water is always supplied to the water tank 10, and the same amount of water is always drained from the water tank 11.

The above description is one embodiment of the present invention, and the present invention can be implemented in various ways other than the above. For example, water tank 10
The vertical drive mechanism 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.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view of a steel pipe immersion hardening apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view of a water level adjusting apparatus according to the present invention. 1... Steel pipe, 2... Conveyance roller, 3... Pipe,
, 4... Support, 5... Base, 9... Rotating roller,
10...Water tank, 11...Quenching water tank, 19...
First arm, 20... Second arm, 21... Steel pipe scooping arm, 25... Inclined guide, 26... Endless rotation device, 29, 30. 31... Dog, 32 ...
Underwater skid, 33... Cylinder device for driving the presser roller 34... Presser roller.

Claims (2)

[Claims] (1) Steel pipe immersion in which 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 quenching apparatus, an endless rotating device having an inclined guide formed with a slope extending from above the quenching water tank to a rotating roller position in the water tank, and a plurality of dogs spaced apart from each other on the outer surface. a carry-in device that performs rectangular movements such as ascending, advancing, descending, and retreating to drop the steel pipe on the conveying roller between the dog of the endless rotating device and the inclined guide; and a carrying device installed above the rotating roller. An immersion hardening apparatus for steel pipes, comprising a presser roller that moves up and down with respect to the rotating roller, and a water level adjustment device that raises and lowers the water level in the hardening water tank. (2) The water level adjustment device includes a water tank that can move up and down with respect to the quenching water tank, and communicates both water tanks with a pipe, and drives the water tank upward and downward to drive the quenching water tank up and down. The steel pipe immersion quenching apparatus according to claim 1, characterized in that the water level of the water tank is changed.