JPH042725A - Method and apparatus for quenching ball screw with non-oxidizing high frequency - Google Patents

Abstract

PURPOSE:To effectively execute non-oxidizing high frequency quenching to a ball screw without forming scale by automatically and continuously conveying the ball screw into a non-oxidizing chamber through a pre-atmospheric chamber and taking out the ball screws after executing high frequency heating, dipping into cooling water and cooling. CONSTITUTION:The ball screws W1, W2... are conveyed into the pre-atmospheric chamber 10 filled up with non-oxidizing or reducing gas through walking beams 91, 92. Successively, the ball screw W is conveyed to the non-oxidizing chamber 20 filled up with the above gas and mounted on straightener rollers 40 and ascended to heating position through a work lifting device 50. In there, the ball screw W is heated with high frequency heating coil 30 for the prescribed time while being rotated with a work supported rotating device (not shown in the figure). After that, the ball screw W is descended and dipped into cooling liquid l1 in a cooling liquid tank 100 and cooled by injecting the cooling liquid l1 from a jacket 101. The ball screw W after cooling is shifted to out of the cooling liquid tank 100 through an ascending device 60 and carry-out device 70. By this method, the ball screw W is automatically and effectively quenched with non-oxidizing high frequency without forming the scale on the surface.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides for ball screws to be subjected to induction hardening, particularly induction hardening, or non-oxidation induction hardening.
The present invention relates to a method for forming a hardened layer on a ball screw in an atmospheric gas, and an apparatus for applying the method to a ball screw.

<Conventional technology> Conventionally, in order to harden the surface of a ball screw by induction hardening, the ball screw is usually rotated about its longitudinal axis, and the ball screw is moved in the longitudinal direction while facing the ball screw. A high-frequency current is applied to saddle-shaped semi-open high-frequency heating coils that are placed close together so that the
The surface of the ball screw is heated by the induced current generated in the ball screw, and then a cooling liquid is injected onto the heated surface to harden the surface of the ball screw.

<Problems to be Solved by the Invention> However, when such a conventional hardening method is used, a black scale is formed on the surface of the hardened layer. Then, in order to remove the scale formed on the transfer surface of the balls of the ball screw, the transfer surface must be processed or polished. This processing or polishing takes time and effort.

The present invention was devised in view of the above circumstances, and provides a method and device for non-oxidation induction hardening of a ball screw in which scale is not formed on the surface of the ball screw when the ball screw is induction hardened. It is an object.

Means for Solving the Problems> In order to solve the above problems, the non-oxidation induction hardening method for ball screws of the present invention includes a step of transporting the ball screws into a preliminary atmosphere chamber filled with a non-oxidizing or reducing gas. and a step of carrying the ball screw into the non-oxidation chamber filled with the gas and then heating it with high frequency; and a step of immersing the heated ball screw in a cooling liquid and transferring it to the outside of the cooling liquid after being cooled; This is done automatically and continuously.

Further, the non-oxidation induction hardening device for ball screws of the present invention includes a preliminary atmosphere chamber filled with a non-oxidizing or reducing gas, and a preliminary atmosphere chamber which is connected to the preliminary atmosphere chamber and is filled with the gas to perform high frequency heating of the ball screw. a non-oxidation chamber in which the oxidation is carried out, a coolant tank containing a coolant that immerses the lower portions of the two chambers, a means for transporting the ball screw from the atmosphere through the preliminary atmosphere chamber to the non-oxidation chamber, and a means for transporting the ball screw into the non-oxidation chamber. A correction roller on which the ball screw placed on the correction roller is placed, a workpiece support rotation device that supports both ends of the ball screw placed on the correction roller and rotates the ball screw, and a saddle-shaped half-opening device that heats the ball screw supported by the workpiece support rotation device. A work lifting device that raises a ball screw placed on a straightening roller and supported at both ends by a work supporting and rotating device to a heating position together with a straightening roller and a work supporting and rotating device, and then lowers into a cooling liquid after heating. A jacket is provided in the cooling liquid and cools the ball screw by injecting the cooling liquid onto the ball screw, and means for transferring the cooled ball screw to the outside of the cooling liquid tank.

Effect〉 The ball screw is carried into the preliminary atmosphere chamber from the atmosphere, and after the atmosphere that has entered the preliminary atmosphere chamber is replaced by the incoming gas, the ball screw is carried into the non-oxidation chamber while being completely isolated from the atmosphere. It is placed on a correction roller, and both ends are supported by a workpiece support and rotation device. The ball screw is lifted by the work lifting device to the position of the high frequency heating coil, and is heated by the high frequency heating coil for a predetermined time while being rotated on a correction roller by the work supporting rotation device.

After this heating, the ball screw is lowered into the cooling liquid by the work lifting device while being rotated, and the cooling liquid is injected from the jacket to the ball screw in the cooling liquid, thereby cooling the ball screw.

When the cooling of the ball screw is completed, the rotation of the ball screw by the workpiece support and rotation device is stopped and the ball screw is transferred out of the cooling liquid.

<Example> Figs. 1 to 5 are drawings for explaining an embodiment of an apparatus capable of realizing the non-oxidation induction hardening method for a ball screw of the present invention, in which Fig. 1 is a schematic configuration diagram; Figure 2 is a side view of the correction roller, Figure 3 is a front view of the workpiece support rotation device and correction roller, Figure 4 is a side view of the correction roller and workpiece extrusion device, and Figure 5 is an explanatory diagram of the operation of the walking heel. be.

The non-oxidation induction hardening device for ball screws of this embodiment has a pre-atmosphere chamber 10 with an open bottom, which has a shutter S at one end and a shutter S2 at the other end, and is connected to the pre-atmosphere chamber 10 via a shutter 32. It has a non-oxidation chamber 20 which is also open at the bottom, and a coolant tank 100 which is provided below the preliminary atmosphere chamber 10 and the non-oxidation chamber 20. A coolant lI is contained in the coolant tank 100, and the lower portions of the preliminary chamber 10 and the non-oxidation chamber 20 are immersed in this coolant l. In addition, the workpiece ball screw W
A walking beam 91 on which a ball screw W is placed and moved between the atmosphere and the preliminary atmosphere chamber 10, and a walking beam on which a ball screw W is placed and moved between the preliminary atmosphere chamber 10 and the non-oxidation chamber 20. A beam 92 is provided.

Further, the non-oxidation induction hardening device for ball screws of this embodiment includes a correction roller 40 as a means for correcting the distortion of the ball screw W carried into the non-oxidation chamber 20 and rotatably holding the ball screw W, and a ball screw. A workpiece support and rotation device 32 that supports and rotates both end surfaces of the W, and a correction roller 4
A saddle-shaped semi-open high-frequency heating coil 30 heats a ball screw W placed on a ball screw W placed on a correction roller 40 and a ball screw W placed on a correction roller 40 and supported by a workpiece support rotation device 32.
A work lifting device 50 that raises the workpiece to the heating position and places it on land in the cooling liquid after heating, and the cooling liquid! , a pair of jacket eyes 01.101 for injecting a cooling liquid onto the ball screw W from both sides thereof, and a straightening roller 41 for moving the ball screw W, which has finished cooling in the cooling liquid, to the work lifting device. .44 onto the guide plate 58 and the ball screw W with the cooling liquid I! ,1
A work lifting device 60 that lifts the workpiece up into the atmosphere from inside, a workpiece unloading device 70 that transports the ball screw W out of the main hardening apparatus, and atmospheric gas G is supplied to the preliminary atmosphere chamber 10 and the non-oxidation chamber 20. A gas supply means 80 is provided.

The gas supply means 80 supplies a non-oxidizing gas G such as nitrogen or argon, or a reducing gas G such as hydrogen. Preliminary atmosphere chamber 1
0, a gas supply hole 83 for receiving the atmospheric gas G from the gas supply means 80 is provided in the lower part, and a gas exhaust hole 84 for discharging the atmospheric gas G is provided in the ceiling part. Further, the non-oxidation chamber 20 is also provided with a gas supply hole 81 at the bottom and a gas discharge hole 82 at the top.

As shown in FIG. 1, the non-oxidizing chamber 20 is formed into a hollow cylindrical shape, and a high-frequency heating coil 30 is attached to the side wall 21 of the non-oxidizing chamber 20 via a skirt 31 near the top. .

As shown in FIG. 2, the straightening roller 40 includes a pair of rollers 41, 41 attached to a shaft 42 supported by a bearing 43;
a roller 44 attached to a shaft 45 supported by a bearing 46;
A roller mounting base 47 to which bearings 43 and 46 are fixed, and a roller rotation motor 48 provided on the roller mounting base 47 (Fig. 3)
It is equipped with In this embodiment, one set of correction rollers 40 is provided, but a plurality of sets of correction rollers are provided depending on the length of the ball screw l.

As shown in FIG. 3, the workpiece support rotation device 32 includes a ball screw end support device 3 that supports one end of the ball screw W.
3 and a chuck 35 that grips the other end are arranged to face each other. The ball screw end support device 33 and the chuck 35 are provided with a ball screw end support device moving cylinder 3 that moves the ball screw end support device 33 and the chuck 35 in the longitudinal direction of the ball screw W, respectively.
4 and a chuck moving cylinder 36 are provided. 37 is a chuck rotation motor. Note that the ball screw end support device moving cylinder 34 and the chuck moving cylinder 36 are mounted on a roller mounting base 47 of the correction roller 40. Both the motor 37 and the roller rotation motor 48 are waterproof, and the non-oxidation chamber 2
Power is supplied from a power supply box (not shown) provided inside the motor 37, 48 through a cabtire cord (not shown), so that these motors 37, 48 can operate without abnormality even if they are immersed in the coolant f.

The work lifting device 50 is located at the bottom 10 of the cooling liquid tank 100.
2, and a rod 51 that moves forward and backward by the cylinder 52.
A roller mounting base 47 of the correction roller 40 is fixed to the tip of the correction roller 1 .

As shown in FIG. 4, a work extrusion device 56, which serves as a means for extruding the ball screw W from above the correction roller 40, is attached to a support 53 erected at the bottom 102 of the coolant tank 100, and is attached almost horizontally to the top of the support 53. a cylinder 54,
This cylinder 54 advances and retreats, and when it advances, it pushes the ball screw W placed on the correction roller 41, 44, and the ball screw W is moved from above the correction roller 40 to the guide plate 5.
8.

The work lifting device 60 moves from the correction roller 40 to the guide plate 5.
A workpiece support member 63 that supports the ball screw W that has fallen through 8 between the wall of the coolant tank 100, a rod 61 attached to the lower part of this workpiece support member 63, and a rod 61 that advances and retreats. A cylinder 62 is provided. The workpiece unloading device 70 is a plate material that is inclined and disposed close to the coolant tank 100 so that the ball screw W placed on the workpiece unloading device 70 is rolled and transported.

Coolant stored in the coolant tank 100! , is high speed quench oil or bright oil, etc., and this coolant 11 is the coolant! A pair of jackets 101, 101 are provided in the cooling liquid 11, which inject and rapidly cool the ball screw W immersed in the cooling liquid 11.

A plurality of equally spaced V-shaped grooves 93 in which ball screws W are placed are formed in the walking beams 91 and 92. A fixed beam on which the ball screw W conveyed by the walking beams 91 and 92 is placed for each step, and a groove provided for placing the ball screw on this fixed beam are not shown. 200 is a high frequency power source that supplies high frequency current to the high frequency heating coil 30.

Next, the operation of hardening the ball screw W using the non-oxidation induction hardening device for a ball screw of this embodiment will be described.

The walking beams 91 and 92 repeatedly move in four steps in the directions of arrows A, BSC, and D, as shown in FIG. After completing these four stages of movement,
The ball screw W advances one groove (not shown) of the aforementioned fixed beam (not shown) and is placed in the next groove (hereinafter, this will be referred to as the ball screw W moving forward one step).

The first ball screw W is first placed in the first groove of the fixed beam (not shown), which corresponds to the groove 93 at the right end (right end in the figure) of the walking beam 9I.

As the walking beams 91 and 92 repeatedly move through the four steps described above, the ball screw W advances one step at a time. When the ball screw W moves forward by the first step, the second ball screw W2 (the second ball screw is designated by the symbol W2. Hereinafter, the third, fourth, etc. ball screws are similarly designated W3, W4, etc.).・)
is placed in the groove in which the ball screw W was placed at the beginning of the fixed beam.

Thereafter, ball screws W3, W4, . . . are placed one after another.

By the movement of the walking beams 91 and 92, the ball screw W is carried into the non-oxidation chamber 20 through the preliminary atmosphere chamber 10. However, while the walking beams 91 and 92 are moving in the directions of arrows B, C, and D, the shutters S1 and 32 are open, and are closed at other times.

At this time, the ball screw W carried into the non-oxidation chamber 20 by the walking beam 92 is moved to the work lifting device 5.
At the same time, both ends of the ball screw W are placed on the correction roller 40 raised by the workpiece support rotation device 32, and the ball screw end support device moving cylinder 34 and the chuck moving cylinder 36 of the workpiece support and rotation device 32 operate so that both ends of the ball screw W are turned into ball screw ends. It is supported between the section support device 33 and the chuck 35.

Next, the cylinder 52 of the work lifting device 50 is operated to raise the roller mounting base 47 and the ball screw W is positioned between the high frequency heating coils 30, and then the chuck rotation motor 37 and the roller rotation motor 48 are stopped. Start and rotate the ball screw W. Then, a high frequency current is applied from the high frequency power supply 200 to the high frequency heating coil 30 to heat the ball screw W for a predetermined period of time.

When this heating is completed, the cylinder 52 is operated to move the rod 51 backward, and the rotating ball screw W is moved to the coolant 2 in the coolant tank 100 together with the correction roller 40 and the workpiece support rotation device 32. 1 installed in the coolant tank 100 while continuing to rotate the ball screw W.
Coolant from the pair of jackets 101.101! , is injected onto the ball screw W to rapidly cool the pole screw W.

When the ball screw W has finished cooling, the chuck rotation motor 37 and the roller rotation motor 48 are stopped, and the cylinder 54 of the work extrusion device 56 is operated to move the rod 55.
When advanced, the ball screw W is pushed out from above the rollers 41, 44, transferred over the guide plate 58, reaches above the workpiece support member 63, and stops against the side wall of the coolant tank 100. Next, the cylinder 62 is operated to release the rod 6.
1, the ball screw W will move toward the coolant tank 100.
As soon as it leaves the liquid level of the cooling liquid 11 and crosses the side wall of the cooling liquid tank 100,
0 and is transported to a predetermined location by the workpiece transport device 70.

As described above, according to this embodiment, the ball screw W is extremely effectively non-oxidized and induction hardened.

The ball screws W, , W3, etc. following the ball screw W are similarly hardened.

<Effects of the Invention> As explained above, the method and apparatus for non-oxidizing induction hardening of a ball screw of the present invention includes the steps of transporting the ball screw into a preliminary atmosphere chamber filled with a non-oxidizing or reducing gas;
The ball screw is carried into the gas-filled non-oxidation chamber and then heated by high frequency; and the heated ball screw is immersed in a cooling liquid, and after being cooled, the ball screw is transferred to the outside of the cooling liquid. We make sure that it is carried out according to the objectives.

Therefore, according to the method and apparatus for non-oxidation induction hardening of a ball screw of the present invention, effective non-oxidation induction hardening can be performed on a ball screw. Therefore, since scale is not formed on the ball transfer surface of the ball screw, it is possible to eliminate the need for polishing or processing to remove scale after hardening.

[Brief explanation of the drawing]

1 to 5 are drawings for explaining an embodiment of an apparatus capable of realizing the non-oxidation induction hardening method for ball screws of the present invention, in which FIG. 1 is a schematic configuration diagram and FIG. 2 is a straightening 3 is a front view of the workpiece support rotation device and the correction roller, FIG. 4 is a side view of the correction roller and the workpiece extrusion device, and FIG. 5 is an explanatory diagram of the operation of the walking beam. 10... Preliminary atmosphere chamber, 20... Non-oxidation chamber, 30...
... High frequency heating coil, 32 ... Workpiece support rotation device, 40 ... Correction roller, 50 ... Workpiece lifting device,
60... Workpiece lifting device, 70... Workpiece unloading device, 91.92... Walking beam, 100
,...coolant tank, 101-...jacket,! 1
... Coolant, W, Wz~W7 ... Ball screw. Figure 2 Patent Applicant: Fuji Electronics Co., Ltd. Agent, Patent Attorney Takaharu Ohnishi Figure 3

Claims (2)

[Claims] (1) The process of transporting the ball screw into a preliminary atmosphere chamber filled with non-oxidizing or reducing gas, the process of high-frequency heating after transporting the ball screw into the non-oxidizing chamber filled with the gas, and the cooling of the heated ball screw. 1. A method for non-oxidation induction hardening of a ball screw, comprising a step of immersing the ball screw in a liquid, cooling it and then transferring it out of the cooling liquid, and said step being automatically and continuously carried out. (2) A preliminary atmosphere chamber filled with a non-oxidizing or reducing gas, a non-oxidizing chamber connected to the preliminary atmosphere chamber and filled with the gas to perform high-frequency heating of the ball screw, and a lower part of both chambers. A cooling liquid tank containing a cooling liquid to be immersed, a means for transporting the ball screw from the atmosphere through a preliminary atmosphere chamber to the non-oxidation chamber, a straightening roller on which the ball screw carried into the non-oxidation chamber is placed, and a straightening roller. A workpiece support and rotation device that supports both ends of the ball screw placed on it and rotates the ball screw, a saddle-shaped semi-open high-frequency heating coil that heats the ball screw supported by the workpiece support and rotation device, and a workpiece placed on the correction roller. A work lifting device that raises the ball screw, both ends of which are supported by a support rotation device, together with a correction roller and a work support rotation device to a heating position and then lowers into a cooling liquid after heating, and a work lifting device that is installed in the cooling liquid and injects the cooling liquid onto the ball screw. 1. A non-oxidation induction hardening device for a ball screw, comprising: a jacket for cooling the ball screw; and means for transferring the cooled ball screw to the outside of a cooling liquid tank.