JPS60230938A - Detection of starting position for hardening treatment by remelting - Google Patents

Abstract

PURPOSE:To eliminate variance in positioning and to perform satisfactorily a hardening treatment by remelting by detecting the side edge of a part to be treated by a means for detecting position which moves integrally with a base and setting the starting position for treatment of a torch. CONSTITUTION:A material to be treated such as a preheated cam shaft 8 is disposed between a work shuck 12 and a center 15. The base 21 is laterally moved and the torch 20 is vertically moved to dispose the nozzle part 26 of said torch to face a cam part 8-1 at the left end by maintaining a prescribed clearance from the cam surface. As the base 21 moves, a sensor 41 for detecting position in the integral relation therewith moves. When the end face position of the cam surface in the cam part 8-1 is detected, the detection signal thereof is fed to a control device 39 and the movement of the base 21 stops. The positions of the sensor 41 and the torch 20 are preliminarily set by providing an offset therebetween, by which setting of the torch 20 to the reference position for starting the hardening treatment by remelting is made possible.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a process start position detection method for remelting and hardening a plurality of cam parts in a camshaft, for example.

(Prior art) Remelting and hardening J! is a surface hardening treatment for the cam surface of the cam portion of the camshaft. ! (Remelt treatment) is in practical use. In this case, the engine camshaft usually forms multiple cam parts, so the camshaft set in the jig must be sequentially remelted and hardened with a plasma torch on the cam surface of each cam. The fixed position of this camshaft is predetermined, and the plasma torch moves to the portion of the camshaft to be treated to perform the treatment. However, the camshaft is formed from a cast material, and as a result, there are variations in the accuracy of the product dimensions. The control of the movement of the plasma torch is programmed in advance, so if there are variations in dimensional accuracy, unprocessed areas may occur on the cam surface, or deformation of the cam portion may occur due to overrun of the plasma torch. There is. In order to solve this problem, it is necessary to improve the machining accuracy of the material before remelting and hardening, but this is difficult in practice.

(Object of the Invention) The present invention provides a method for remelting and hardening a workpiece having a plurality of workpieces, such as an engine camshaft, by accurately detecting the position of the workpiece. The purpose is to eliminate the need for high processing accuracy on the material before processing, eliminate the effects of positioning variations, and enable high-quality remelting and hardening. .

(Structure of the Invention) The present invention provides a method for performing remelting and hardening treatment by moving and disposing a torch attached to a base that can freely move in the axial direction of a workpiece to be treated. A position detecting means that moves together with the base and faces the object to be processed is provided, and this position detecting means detects at least one of both edges of the object to be processed. The gist is that the starting position of the torch remelting and hardening process is set in .

(Embodiment) A preferred embodiment of the present invention will be described below based on the accompanying drawings.

First, the overall structure of the remelting and hardening processing apparatus according to the present invention will be explained based on FIGS. 2, 3, and 4. FIG. 2 is a front view with a part of the front side omitted, FIG. 3 is a plan view, and FIG. 4 is a side view.

In Figures 2 and 3, (1) is a preheating section, and the preheating section (1) is equipped with a motor (3) having a workpiece chuck (2) in its rotating section, and a center (4). An axial pressing cylinder (5) is arranged on the base (6) in front of the table (7) at a constant interval. A camshaft (8) supported by the workpiece chuck (2) and the center (4) is disposed before being subjected to remelting and hardening treatment, and is rotated by the operation of the motor (3). It is heated by a high frequency heating coil (8).

The preheated camshaft (8) is transferred to an adjacent processing section (11) located at the back of the table by a loader (10) disposed above.

The processing section (11) is a station that performs remelting and hardening processing. Also in the processing section (11), the camshaft (8)
A motor (14) having a workpiece chuck (12) via a deceleration mechanism (13) for supporting and fixing the workpiece, and a center (
15) and an axial pressing cylinder (16). In this case, the axial pressing cylinder (16) is guided by guide bars (17a), (17a) installed on the support frame (17) on the table (7), and can move to the left in FIG. It is configured as follows.

A support frame (18) is provided diagonally above the camshaft (8) supported by the chuck (12) and the center (15) on the back side of the table (7). This support frame (18
), guide bars (z9), (ts) are installed vertically apart between the left and right vertical frame parts (18a), (18a) in FIG. The guide bars (19), (19) are the base (2) for the plasma torch (20) for remelting and hardening treatment.
1), and ensures that the torch (20) moves in the left and right directions in FIG. A feed screw (22) is rotatably installed horizontally between the upper and lower guide bars (19), (19), and this feed screw (22) is screwed into the base (21) via a pole screw mechanism. There is. The feed screw (22) is attached to the vertical frame part (18a) on the left side in Figures 2 and 3.
) A transmission mechanism (20
The motor (23) drives the motor (23) in forward and reverse rotation.

Further, a holder (25) for holding the plasma torch (20) is provided on the base (21) so as to be movable downward. Therefore, a motor (21a) is provided within the base (21) to move the holder (25) up and down. The plasma torch (20) held in the holder (25) has its tip facing downward, and the workpiece chuck (12) and the center (
The camshaft (8) is disposed at an upper position of the camshaft (8) disposed between the camshaft (15) and the camshaft (8) so that its axis is in the vertical direction.

A nozzle portion (26) as shown in FIG. 5 is provided at the tip of the plasma torch (20). In the nozzle part (26), a chip (28) is disposed within a shield cap (27), and a passage (29) for shielding gas is provided between them.
is formed. A working waste passage (30) is formed in the center of the chip (28), and a cooling passage (31) is formed around it. (32) is an electrode made of tungsten or the like.

In addition, the shield cap (27) has no metal powder introduced into the tube (3).
3), (33), the extension line of the axis is the passage (30)
It is inserted and fixed so as to intersect with the extension line of. A molten pool is formed on the outer surface of the cam part (8-1) of the camshaft (8) by the discharge by the electrode (32) of the nozzle part (26) and the plasma of the working gas, while a molten pool is formed on the outer surface of the cam part (8-1) of the camshaft (8). (33
) and (33), the remelting and hardening process is performed while supplying the metal powder from (33).

In FIG. 1, (34) is a plasma power supply, which supplies the required power to the electrode (32) of the plasma torch (20). In addition, (35) is a powder supply device, and while applying vibration with a vibration device (3B), the pipe line (37) is
, (37) to the pipe (33) into which the metal powder has not been introduced.

(33) Supply metal powder. Pipeline (37)
.

A detection device (38) for checking the supply of powder is disposed in the middle of (37).

Further, in FIG. 1, (39) is a control device.

The control device (39) has a built-in computer and controls the aforementioned work rotation motor (14), the motor (23) for laterally moving the torch (20), and the torch (20) according to a pre-installed program. A control signal is given to instruct the motor (21a) in the base (21) to move in the vertical direction. Generally, a servo motor or a pulse motor is used for each of the above-mentioned motors. At the same time, the control device (38) also controls the plasma power source (34).
, the powder supply device (35), and the vibration device (3B).

Next, in FIG. 1, a camshaft (8) extending downward from the base (21) and fixedly installed between the work chuck (12) and the center (15) is installed. A position detection sensor (41) disposed on the attached mounting piece (40) is a position detection sensor that detects the position of the cam part (8). Although the position of the sensor is shown below the camshaft for convenience of explanation, the actual position is from the right side of the work as shown in FIG. The position detection sensor (41) is
For example, an output section (41a) that generates light, magnetism, ultrasonic waves, etc.
and an input section (41b) that receives these reflected back by the detection target. This sends information related to the detection target to the control device 21 (39). Generally, a sensor using laser light is most suitable for this position detection sensor (41).

Next, a method of remelting and hardening the cam portion of the camshaft (8) will be explained.

The camshaft (8) preheated in the preheating section (1) is transferred to the Rogue (10), and the work chuck (12) and center (
15) Place and fix between. Next, the motor (23)
The base (21) is moved laterally by the action of the feed screw (22), and the holder (25) is moved downward by the motor (21a) of the base (21). The torch (20), which was in a standby state in this way, is moved against the first cam portion (8-1) at the left end of the camshaft (8) as shown in FIG.
The nozzle portion (2B) is arranged with a predetermined clearance maintained between it and the cam surface.

In the above, when the base (21) starts to move in the right direction, the position detection sensor (41) that is integrally connected to the base (21)
) also moves. The position detection sensor (41) facing the camshaft (8) detects the position from its output part (41a) to the camshaft (
8) For example, a laser beam is emitted.

The reflected light is received by an input section (41b) consisting of a camera or the like. When the detected target portion becomes the end face, which is one edge of the cam surface of the cam part (8-1), the position of this end face is detected, and this detection signal is sent to the control device (39). ) movement is stopped.

The positions of the position detection sensor (41) and the torch (20) are set in advance with an offset amount, so that the torch (20) can be set at the reference position at which the remelting and hardening process is started.

In addition, in finding the reference position, it is also possible to detect the end face, which is the other edge of the cam part, and to determine the position. Further, by detecting the positions of both end faces of the cam part, the position of the cam part on the camshaft and the width of the cam part can also be accurately detected.

Furthermore, after detecting one of the end faces, the starting position of the remelting and hardening process may be set by further moving based on the detected position.

In this state, the nozzle part (26) of the torch (20)
), the cam surface of the cam portion (8-1) of the camshaft (8) is subjected to remelting and hardening treatment as shown in FIG. 5 described above. In this case, the camshaft (8) is connected to the motor (
14), the torch (20) is rotated at low speed via the deceleration mechanism (13), while the height of the cam part (S-t) is changed to maintain a constant clearance between the tip of the torch (20) and the cam surface. The cam part (
The torch (20) is laterally reciprocated within the width of the cam surface of 8-1). Torch (20) (7) The vertical movement is controlled by the motor (21a) in the base (21), and the reciprocating movement is controlled by the motor (23) by the control device W (
39).

In this way, the remelting and hardening process is performed while drawing a meandering locus (A) on the cam surface of the cam portion (8-1) as shown in FIG.

When the remelting and hardening process in the cam part (8-1) is completed as described in 2., the base (21) starts to move rightward based on the command from the control device (38), and the adjacent cam Repeat the above operation for the section. In this way, all the cam parts are sequentially remelted and hardened, and after the process is completed, the torch (2o) is moved to the standby position,
Control is made to wait again. After the camshaft (8) that has been subjected to the remelting hardening treatment is replaced with a new camshaft that has not been subjected to treatment, the same treatment as described above is performed on this new camshaft. Repeat this from now on.

(Effects of the Invention) As is clear from the above explanation, according to the present invention, when remelting and hardening engine camshafts, etc., which tend to have variations in the dimensions of the material due to the manufacturing method, each Since the processing start position for the material is set by detection, remelting and hardening treatment with a good finish can be performed despite dimensional variations in the material. Furthermore, there is no need to increase the precision of material processing before remelting and hardening, and processing can be performed easily. Furthermore, it exhibits various features such as being able to eliminate the effects of positioning variations that occur when placing materials on workstations.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a control system of a remelting hardening treatment apparatus according to the present invention, and FIG. 2 is a front view of the same remelting hardening treatment apparatus.
Fig. 3 is a plan view of the device, Fig. 4 is a side view of the device, Fig. 5 is an enlarged vertical sectional view of the nozzle part of the plasma torch, and Fig. 6
The figure shows the processing locus of the torch on the cam surface of the cam part. In the drawings, (ri indicates preheating section, (3), (14), (23),
(21a) is a motor, (5) and (1B) are axial pressing cylinders, (8) is a camshaft, (9) is a high-frequency heating coil, (1O) is a Rogue, (11) is a remelting hardening processing section, (18) is a support frame, (19), (19) is a guide bar, (20) is a plasma torch, (21) is a base of a plasma torch, (22) is a feed screw, (25) is a holder of a plasma torch, (26) is the nozzle part of the plasma torch, (39) is the control device, (41) is the position detection sensor, and (A) is the processing trajectory. Patent applicant Honda Motor Co., Ltd.

Claims (1)

[Scope of Claims] A method for performing remelting hardening treatment by moving and placing a torch attached to a base that can freely move in the axial direction of a workpiece to be treated on the workpiece. A position detecting means that moves integrally with the base and faces the object to be processed detects at least one of both edges of the object to be processed, thereby redirecting the torch in the area to be processed. A method for detecting a process start position in a remelting hardening process, comprising: setting a melt hardening process start position.