JPS63286510A - Treating apparatus for remelted hardening - Google Patents

Abstract

PURPOSE:To execute the remelted hardening treatment with uniform quality to a casting by arranging means controlling shaking rate of vertical link and setting inclining angle and interval distance of a heating torch to the casting to the fixed value. CONSTITUTION:Following shafts 22 and driving shafts 21 are shakably arranged at front/rear end parts of supporting member 20 of shaking mechanism 2. The upper end part of the vertical link 23 is fitted at part positioned between flat plates 20a of the driving shafts 21 and a horizontal link 24 is fitted at inside of the vertical link 23. At the time of shaking the vertical link 23 toward front/ rear direction, the following shaft 22 is shaked as the same rate as the driving shaft 21, to restrict the shaking rate of the torch 4. By command from an arithmetic and control unit 5, a motor 29 is driven and at the time of oscillating a cam shaft 3, the torch is shaken and the distance between the lower end of the torch 4 and the casting product of cam 30, etc., is always set to constant. Further, the arithmetic and control unit 5 attitude-controls shaking rate and shaking direction of the torch 4, so that the axial center of the torch 4 always becomes vertical to the peripheral face of the cam 30.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a remelting and hardening method provided for forming a chill layer on the circumferential surface of a cast product such as a roller, for example, in order to harden the circumferential surface of the cast product. The present invention relates to a processing device, and more specifically, to a remelting and hardening processing device for hardening cast products having circumferential surfaces with different radii of curvature, such as cams, camshafts for vehicles, and the like.

Figures 5(a) and 5(b) show a conventional example of such a remelting and hardening treatment apparatus, in which the camshaft 3 is
It has a structure in which the peripheral surface 310 of 00 is melted to form a chill layer. In addition, a shielding gas 820 such as Ar is ejected from the tip of the torch 40 so as to surround the electrode 830 and the arc 810 in order to prevent the generation of blowholes and burnout of the electrode 830 of the torch 40. It has become. Further, the torch 40 is connected to the camshaft 30
The camshaft 300 is designed to perform oscillating motion (vibration) in the thickness direction of the camshaft 300, that is, in its axial direction, and the camshaft 300 rotates around the shaft 320.

However, in the case of the above-mentioned conventional example, it is not possible to prevent the generation of blowholes and burnout of the electrode 830 due to the following reasons, and it is not possible to prevent a uniform chill layer on the peripheral surface 31. As a result, accurate remelting and hardening cannot be performed, and furthermore, the polishing process in the post-process becomes troublesome.

That is, (1) Since the torch 40 is caused to perform an oscillating motion, if the cycle of the oscillating motion is accelerated in order to improve production efficiency, the flow of the shielding gas 820 will be disturbed, and a good shielding effect will not be achieved. This cannot be expected, and a blowhole will occur, and the electrode 830 will be burnt out.

(2) Since the torch 40 is fixed in the rotational direction of the camshaft 300, the ejection direction (incident angle) of the arc 810 with respect to the circumferential surface 310 changes according to the rotation of the camshaft 300. Then, the distance l between the tip of the torch 40 and the circumferential surface 310 of the camshaft 300 changes, and the ejection direction of the arc 810 and the axis of the torch 40 shift as shown in FIG. 5(b). Therefore, the remelting point (remelting position) 800 is not constant in the circumferential direction of the camshaft 300, resulting in a problem that the melting depth differs in the circumferential direction. Further, since the flow of the shielding gas 820 is disturbed, blowholes are generated in the same manner as described above. Furthermore, the molten part will flow.
This causes "sag" and unevenness in the thickness direction on the hardened surface, which increases the polishing process in the subsequent process.

The present invention has been made to solve the problems of the prior art, and is suitable for remelting and hardening cast products having peripheral surfaces with different radii of curvature, such as cams and camshafts for vehicles. It is an object of the present invention to provide a remelting hardening treatment apparatus that can perform a homogeneous hardening treatment and can efficiently perform polishing in a subsequent process.

. - A remelting hardening treatment apparatus according to the present invention for forming a chill layer by remelting the peripheral surface of a cast product having peripheral surfaces with different radii of curvature. means for vibrating the cast product in the thickness direction; a main rotating body having a circumferential surface corresponding to the circumferential surface of the cast product and rotating in conjunction with the cast product; a vertical link, a driving means for swinging the vertical link, a rotation shaft portion at the tip and base end, and the base end is rotatably connected to the upper end of the vertical link. A horizontal link, a heating torch connected to the rotating shaft on the tip side, and a heating torch connected to both rotating shafts.
a linking means for swinging the heating torch in correspondence with the swinging amount of the vertical link; a support member having a guide groove at its tip and base end for guiding the swing of both rotational shafts; and the support member. Height adjustment that is attached to the middle part of the member, has a subordinate rotary body rolling on the circumferential surface of the main rotary body at the lower end, and sets the separation distance between the torch and the circumferential surface to a constant value. and a controller that controls the amount of swing of the vertical link so as to bring the heating torch directly facing the circumferential surface of the cast product.

Here, "directly facing" means that the axis of the heating torch is approximately perpendicular to the circumferential surface.

When appropriate, the inclination angle of the heating torch with respect to the circumferential surface of the cast product and the separation distance between the tip of the heating torch and the circumferential surface can be set to constant values at all times during the remelting and hardening process.

Souse plate Embodiments of the present invention will be described below based on the drawings.

Fig. 1 is a partially cutaway front view showing a remelting and hardening treatment apparatus according to the present invention, Fig. 2 is a partially cutaway right side view of the main part, and Fig. 3 is a view of Fig. 1 as viewed from direction A. , FIG. 4 is a diagram explaining the principle of the present invention.

This remelting hardening treatment apparatus includes an oscillating mechanism 1 that oscillates a camshaft 3 made of a cast product in the axial direction corresponding to the left-right direction in the figure, and a plurality of cams 30, 30 provided in the axial direction of the camshaft 3. A swinging mechanism 2 that enables a torch 4 that melts a circumferential surface 31 of . The torch 4 is provided with an arithmetic and control device 5 that controls the amount of swing of the torch 4 so that it is always perpendicular to the torch 31, and also controls the cycle of the oscillating motion of the oscillating mechanism 1.

The details of each part will be explained below. The oscillator mechanism 1 includes a movable table 110 that includes a pole screw, a pole nut, etc., and that moves back and forth in the left-right direction in the figure, and a support base 111 that is provided on the movable table 110 so that it can move back and forth in the left-right direction. , a motor 12, a drive shaft 13, etc., which are fixedly arranged on this support base 111.

The movable table 110 is moved by a motor 11 connected thereto.
The processing is performed by the arithmetic and control unit 5 via the controller 2. That is, when the arithmetic and control device 5 issues a predetermined drive command signal to the motor 112, the motor 112 reciprocates the movable table 110 at a predetermined period, and as a result, the drive shaft 13 moves as described below. The camshaft 3 held by the camshaft 3 makes an oscillating motion.

An air cylinder 11 is attached to the left end of the support stand 111 to move it in the left-right direction. The driving of this air cylinder 11 is controlled by an arithmetic and control device 5. That is, when a predetermined drive command signal is issued from the arithmetic and control unit 5 to the air cylinder 11, the rod 11a of the air cylinder 11 advances or retracts, thereby causing the support base 111 to reciprocate. The air cylinder 11 is driven, that is, the support base 111 is moved when the camshaft 3 is set on the drive shaft 13 and when this setting state is released.

A support member 10 having a motor 12 attached to its upper end is fixed to the support stand 111. The output shaft of the motor 12 faces downward, and a reduction gear 14 is connected to this output shaft via a coupling 12a. The reducer 14 transmits the driving force of the output shaft of the motor 12 rotating around a vertical axis to the drive shaft 13 holding the camshaft 3 at its right end, and rotates this around a horizontal axis at a predetermined speed. ing. Note that the drive of the motor 12 is controlled by the arithmetic control device 5.

A drive pulley 102 is fitted to a position near the left end of the drive shaft 13 using a key 101. The drive pulley 102 transmits the rotation of the drive shaft 13 to the master cam 7 shown in FIG. That is, at the rear of the drive pulley 102, a transmission shaft 70 supporting a similar driven pulley (not shown) is rotatably provided at a corresponding position, and an endless transmission shaft 70, which is wound between both pulleys, is rotatably provided. The rotation of the drive shaft 13 is transmitted to the transmission shaft 70 via the timing belt 103, so that both rotate synchronously.

The mechanism for holding the camshaft 3 is as shown in FIGS. 1 and 3. That is, a holding shaft 15 equipped with a centering member 16 is connected to the right end of the drive shaft 13, and a camshaft is connected between this centering member 16 and a centering member (not shown) provided at a corresponding position on the right side. 3 in a horizontal position and in a centered state (setting)
It is supposed to be done. Specifically, this setting is performed by driving the air cylinder 11 and an air cylinder (not shown) provided at a corresponding position on the right side in the approaching direction by the respective rods.

The release of sesoching is performed by driving both air cylinders in a direction in which the respective rods are separated.

Note that the setting of the camshaft 3 is performed prior to the remelting and hardening treatment, and before performing the above-mentioned clamping pressure, the camshaft 3 is first set to the height of the drive shaft 13 using an air cylinder 17 installed on the right side of the drive shaft 13. This is done by setting both air cylinders in a holding position. The drive of this air cylinder 17 is also controlled by the arithmetic control device 5, and when the setting is completed, the loft 17a of the air cylinder 17 is retracted by an excessive command signal from the arithmetic and control device 5, and the camshaft 3 It is designed so that it does not interfere with the rotation of the

As shown in FIG. 3, the outer side of the centering member 16 is fitted with a positioning hole (not shown) provided on the end surface of the camshaft 3 while the camshaft 3 is held on the drive shaft 13. A positioning pin 18 for positioning in the circumferential direction of 3 is provided. This positioning pin 18 is always urged toward the tip side by a coil spring 19. A detection pin 18a is extended in the radial direction from the base end of the positioning pin 18, and the position of the detection pin 18a is detected on the outer side of the detection pin 18a, and this detection signal is sent to the index position of the camshaft 3 in the circumferential direction. A proximity sensor 100 is provided which sends a detection signal to the arithmetic control bag W5.

Here, each cam 30, 30... of the camshaft 3 is supported with its phase individually different from the camshaft, but the index of the camshaft 3 of each cam 30, 30... The amount of phase shift (shift angle) with respect to the position is determined by the arithmetic and control unit 5.
is stored as deviation amount data in the arithmetic and control unit 5.
calculates the remelting and hardening process start position of each cam 30, 30... based on this deviation amount data and the index position detection signal from the proximity sensor 100, drives and controls the motor 12 based on the calculation result, The starting position of the remelting and hardening process is made to follow the position of the torch 4, which will be described below.

Next, the swing mechanism 2 will be explained. A support member 20 is formed by connecting two flat plates 20a, 20a, which are long in the front and back and whose rear ends extend downward, in a left and right direction, and a driven shaft 22 and a drive shaft 21 are installed at the front and rear ends of the support member 20, respectively. It is designed to be able to swing freely. As shown in FIG. 1, two flat plates 23a and 23a are located between the flat plates 20a and 2Oa of the drive shaft 21.
The upper end of the vertical link 23 is attached to the outermost side, and inside the vertical link 23 there are two long flat plates 24a, 24a, which are connected in opposite directions in the left and right directions. Attach the rear end of the link 24 and
A and a drive gear 25a and a drive wheel 26a are provided between 24a and 24a.
It is attached. Collars 27, 27, . . . are interposed between these members.

On the other hand, the front end of the horizontal link 24 and the driven boob IJ26b are attached to the corresponding positions of the driven shaft 22, and a collar (not shown) is similarly interposed between these and the flat plates 20a and 2Oa. . A torch 4 of a TIG welding machine is connected to the right end of the driven wheel 22 protruding from the right flat plate 20a. Note that the front and rear end portions of the horizontal link 24 are rotatable with respect to the drive shaft 21 and the driven shaft 22.

An endless timing belt 28 is wound between the drive pulley 26a and the driven pulley 26b, and a fixed gear 25 that meshes with the drive gear 25a is provided below the drive gear 25a.
b is provided. These gears 25a and 25b function as a brake mechanism that accurately stops the swinging drive shaft 21 at a predetermined position, as will be described later.

Furthermore, a motor 29 is connected to the vertical link 23 via a connecting means (not shown) to swing the vertical link 23 by a predetermined amount in the front and rear directions. The motor 29 is provided on the left side of the swing mechanism 2, and receives a predetermined drive command signal from the arithmetic and control unit 5 to swing the vertical link 23.

Thus, when the motor 29 is driven to swing the vertical link 23 in the front-back direction, the drive shaft 21 swings by an amount corresponding to the swing amount of the vertical link 23.

Then, the drive boo 'J26 attached to the drive shaft 21
Since a moves relative to the timing belt 28 by an amount corresponding to the amount of swing of the drive pulley 26a, the timing belt 28 causes the driven pulley 26b to swing by the same amount as the drive pulley 26a, causing the driven shaft 22 to swing. It is caused to swing in the longitudinal direction by the same amount as the drive shaft 21. Thus, the torch 4 will now swing back and forth.

In addition, as shown in FIG. 2, in front of the flat plates 20a and 20a,
A guide groove 200 is formed at the rear end portion to guide the swinging of the drive shaft 21 and the driven shaft 22 in the front-rear direction. Guide groove 20
0 is formed in an elongated shape that is long in the front and back, and the front and rear ends of this are designed to regulate the amount of swing of the drive shaft 21 and the driven shaft 22, that is, the amount of swing of the torch 4. The entire moving mechanism 2 is raised and lowered by an air cylinder (not shown), and is set to the height position shown in the drawing prior to the remelting and hardening process. When the setting is completed, the air cylinder rod will move in and out, but the master cam 7, which will be described next,
It is supported to prevent it from falling. Note that a suspension mechanism (not shown) is provided above the swing mechanism 2 to prevent excessive load from being applied to the master cam 7, and 203 guides the vertical movement of the swing mechanism 2. It is a guide mechanism that

A height adjustment mechanism 2 is provided on the outer surface of the support member 20 at the front-rear intermediate portion, more specifically at the corresponding position of the right flat plate 20a.
01 is installed. This height adjustment mechanism 201 is for setting the distance between the lower end surface of the torch 4 and the circumferential surface 31 of the cam 30 of the camshaft 3 to a constant value during the remelting and hardening process.

That is, a bearing 202 that rolls on the circumferential surface of the master cam 7 is rotatably attached to the lower end of the height adjustment mechanism 201, and the support member 20, that is, the torch 4 is adjusted according to the rotational position of the master cam 7. The height is variable. Therefore, the shape of the master cam 7 is selected to be similar to the cam 30, and since the master cam 7 and the cam 30 are designed to rotate in synchronization as described above, as a result, from the center of rotation, The torch 4 moves up and down in response to changes in the height position of the circumferential surface 31 whose radius of curvature changes depending on the rotational position. Here, master cam 7
When the rolling surface of the bearing 202 is in contact with the circumferential surface of the master cam 7, the distance between the lower end of the torch 4 and the circumferential surface 31 of the cam 30 is always the same as shown in FIG. ), adjust the height adjustment mechanism 20 so that
Torch 4 determined by the separation distance between Torch 1 and Torch 4, etc.
It is selected after considering the amount of oscillation.

In this way, when the motor 29 is driven by the drive command signal from the arithmetic and control unit 5 and the camshaft 3 is caused to perform an oscillating motion, the torch 4 swings as described above, and the lower end of the torch 4 and the circumferential surface 31 of the cam 30 swing. The separation distance from the terminal is always set to l. Then, the arithmetic and control unit 5
As shown in Figure (a), the amount and direction of swinging of the torch 4 is controlled to control the attitude of the torch 4 so that the axis of the torch 4 is always perpendicular to the circumferential surface 31. There is. This attitude control is performed based on the remelting and hardening process start position. That is, information regarding the profile of the circumferential surface 31 of the cam 300 is stored in the arithmetic and control device 5 in advance, and the information regarding the profile from the remelting and hardening processing position is sequentially read out, and the rotation of the motor 29 is adjusted to follow this profile. The direction and amount of rotation are controlled, and the direction and amount of swinging of the torch 4, that is, the attitude of the torch 4 is controlled.

As a result of this control, as shown in FIGS. 4(a) and 4(b), the torch 4 faces the circumferential surface 31 of the cam 30, and the distance between the two is always set to l. Since the surface will be remelted and hardened, an arc 81 is ejected perpendicularly to the peripheral surface 31 as shown in the figure.
Since the remelting point 8 is constant and there is no risk of turbulence in the flow of the shielding gas 82, it is possible to prevent blowholes from occurring and burnout of the electrode 83.
This means that the chill layer can be formed uniformly in the circumferential direction.

Note that the inclination of the axis of the torch 4 with respect to the circumferential surface 31 of the cam 30 is preferably set to a vertical state for the reasons described above, but is not limited to the vertical state, and may be set to a state of inclination close to this. Of course, you may choose to do so.

Next, a procedure for remelting and hardening the camshaft 3 using the apparatus of the present invention will be described.

First, each air cylinder is driven by a drive command signal from the arithmetic and control device 5 to set the swing mechanism 2 at a predetermined height position, and the camshaft 3 is moved to the drive shaft 13.
Set to . Next, the motor 112 is driven and controlled so that, for example, the leftmost cam 30 is positioned below the torch 4.

Next, the motor 112.12.29 is sent from the arithmetic and control unit 5.
A drive command signal is issued to each of the camshafts 3 to cause the camshaft 3 to perform an oscillating motion.
The arc 81 and the shielding gas 82 are blown out from the torch 4, and the leftmost cam 30 is remelted and hardened. When the remelting and hardening process of the cam 30 is completed, the arc 81 and the shielding gas 82 are stopped from being ejected from the torch 4, and the motor 112.
．． 29 is stopped.

Next, the arithmetic and control unit 5 drives the motor 112 to move the camshaft 3 to the right by a predetermined amount, positioning the second cam 30 from the left below the torch 4, and then moving the second cam 30 from the left in the same manner as above. The cam 30 is remelted and hardened. When the remelting and hardening process of the cam 30 located on the rightmost side is completed, the setting of the camshaft 3 is released as described above, and the remelting and hardening process of the second and subsequent camshafts is performed in the same manner. Execute. Here, the order of remelting and hardening processing of each cam 30, 30, etc. is not limited to the above example, but the remelting and hardening processing is performed sequentially based on information regarding the order set and input to the arithmetic and control unit 5 in advance. Of course, you may also decide to do this.

In the above embodiment, the camshaft 3 may be set using a hydraulic cylinder instead of an air cylinder, and a rotating body such as a roller may be attached to the height adjustment mechanism 201 instead of the bearing 202. Alternatively, a device configuration may be adopted in which a plurality of camshafts 3 can be remelted and hardened at the same time. Furthermore, in the above embodiment, a case was explained in which a camshaft 3 was remelted and hardened as an example of a cast product having a different radius of curvature, but the device of the present invention can be similarly applied to cams, etc. It goes without saying that the same can be applied to the remelting hardening treatment of circularly shaped cast products, and the material of the cast product is not limited to castings, and it goes without saying that it can also be applied to steel materials in the same way. Also,
The torch is not limited to that of a TIG welder, and other torches such as a laser welder may be used.

Further, in the above embodiment, the drive shaft 13, that is, the camshaft 3, is rotated at a constant speed. An embodiment may be adopted in which the circumferential length (circumferential distance with respect to the rotation center angle) is always constant with respect to the rotation angle.

If such an embodiment is adopted, the surface area of the cam 30 subjected to the remelting and hardening treatment by the torch 4 is always the same, so there is an advantage that a more uniform chilled layer can be obtained.

Furthermore, data regarding elongation due to thermal expansion of the camshaft 3 during the remelting hardening process may be set and input into the arithmetic and control device 5 in advance, and the above-described remelting hardening process may be performed based on this data. If such an embodiment is adopted, a more precise remelting and hardening process can be performed, so there is an advantage that a more uniform chilled layer can be obtained.

In the case of the present invention described above, the cast product undergoes oscillating motion, so unlike the conventional example described above, there is no turbulence in the flow of the shielding gas, and there is no risk of blowholes occurring. There is no risk of burning out the electrodes of the heating torch.

In addition, the heating torch can always be directly opposed to the circumferential surface of the cast product during the remelting and hardening process, and the distance between the tip of the heating torch and the circumferential surface can always be set to a constant value. Unlike the conventional example described above, the melting depth can be made uniform in the circumferential direction of the cast product. Also, in this respect, it is possible to reduce the risk of turbulence in the flow of the shielding gas, which further reduces the occurrence of blowholes and burnout of the electrodes. This means that the polishing process in the post-process can be carried out more efficiently.

Therefore, it goes without saying that remelting and hardening of cast products such as rollers, which have a constant distance from the center of rotation, that is, the surface to be remelted and hardened is a circumferential surface, can be performed with high precision.
For the reasons described above, it is possible to accurately remelt and harden cast products having circumferential surfaces at different distances from the center of rotation, such as cams and camshafts for vehicles.

[BRIEF DESCRIPTION OF THE DRAWINGS] Figures 1 to 4 show embodiments of the present invention, with Figure 1 being a partially cutaway front view showing a remelting and hardening treatment apparatus according to the present invention, and Figure 2 being Partially cut away right side of the main part, Figure 3 is the 1st
FIGS. 4(a) and 4(b), which are views viewed from the direction A, are explanatory diagrams of the principle of the present invention. FIGS. 5(a) and 5(b) are explanatory diagrams showing the case where the remelting and hardening process is performed using a conventional apparatus. 1... Oscillating mechanism 11... Air cylinder 12... Motor 13... Drive shaft 100... Proximity sensor 102... Drive pulley 110... Movable table 112... Motor 2... Swing mechanism 20... Support member 21... Drive shaft 22... Driven shaft 23... Vertical link 24... Horizontal link 26a... Drive pulley 26b... Driven pulley 28... Timing Belt 200...Guide groove 202...Bearing 3...Camshaft 30...Cam 31...Surrounding surface 4...Torch 5...Arithmetic control device 7...Master Cam Patent Applicant Fuji Electronics Industry Co., Ltd. Agent Patent Attorney Takaharu Ohnishi Figure 3 Figure 4 (E) Figure 4 (1)) Figure 5 (a) Figure 5 (b)

Claims (1)

[Claims] (1) In a remelting hardening treatment apparatus for forming a chill layer by remelting the circumferential surface of a cast article having circumferential surfaces with different radii of curvature, means for vibrating the cast article in the thickness direction thereof; A main rotating body having a circumferential surface corresponding to the circumferential surface of the cast product and rotating in conjunction with the cast product, a vertical link that is swingable in a vertical plane, and a drive means that swings the vertical link. and a horizontal link having a rotating shaft portion at the distal end thereof and whose proximal end portion is rotatably connected to the upper end portion of the vertical link, and connected to the rotating shaft portion on the distal end side. A certain heating torch, a connecting means that is connected to both rotating shafts and that swings the heating torch in correspondence with the swinging amount of the vertical link, and a guide groove that guides the swinging of both rotating shafts. a supporting member having a proximal end thereof, and a subordinate rotating member attached to an intermediate portion of the supporting member and rolling on the circumferential surface of the main rotating member at a lower end, the torch and the A height adjustment mechanism that sets a distance from the circumferential surface to a constant value, and a controller that controls the amount of swing of the vertical link so that the heating torch directly faces the circumferential surface of the cast product. Characteristic remelting hardening processing equipment.