JPH1034357A - Deburring method after pressure-welding between end faces of round bar shaped work - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate fracture in deburring by friction-welding a round bar shaped work, inserting the friction-welded work in a deburring device, making the work stand by for a prescribed time, and deburring the joined part. SOLUTION: A friction-welded material 3 is inserted in a punch die 13. A pair of photo-sensors 15a, b, sensing the insertion of the material 3, actuate a timer 16. With a prescribed time passing, the timer 16 transmits a signal to a control device. An elevation means is actuated, a punch 14 lowered, and the burrs 4 of the material 3 die-cut. The material 3 after the friction welding is made to stand by for a prescribed time in the punch die 13, with the burrs 4 die-cut in a state where the temperature is low in the joined part 3a of the material 3. As a result, no fractures develop in the joined part 3a. Cooling time is taken in a deburring device; therefore, no influence is imparted to the cycle time of the friction welding device, and no productivity is lowered. Consequently, very few defective products are produced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a round bar-shaped material for producing an engine valve, for example, which is produced at a joint portion when an end surface of an austenitic steel bar and a martensitic steel bar are friction-welded to each other. The present invention relates to an improvement in a method for removing burrs.

[0002]

2. Description of the Related Art Among engine valves, there is a shaft welding valve using austenitic steel and martensitic steel on its umbrella portion side and shaft portion side, respectively.

FIG. 4 shows a process of manufacturing such an engine valve. The end faces of an austenitic steel rod (1) and a martensitic steel rod (2) having a predetermined diameter and a predetermined length are connected to each other.
One round bar-shaped material (3) joined by friction welding
After removing the burrs (4) generated at the joint (3a), the first intermediate (5) is formed by an electric forging machine, and then the second intermediate (6) is formed by a hot press. After formation, each part is machined to obtain an engine valve (7).

FIGS. 2 and 3 show a material obtained by joining the austenitic steel rod (1) and the martensitic steel rod (2).
FIG. 4 is a front view schematically showing a friction welding device and a deburring device for (3).

In the drawing, (8) is a base, (10) is a fixed gripper fixed on the base, (10a) is its chuck, (11)
Is a movable gripper that is coaxially opposed to the fixed gripper (10) and is capable of reciprocating in the left-right direction in the drawing (hereinafter, the direction is referred to as the drawing), (11a) is a rotating chuck that rotates at a high speed, (13) ) Is a punching die for flash removal fixed in front of the base 8 in the up-down direction, and 14 is a punching die (1) by lifting means (not shown).
A punch that moves up and down toward 3).

In the above-mentioned apparatus, as shown in FIG. 2, an austenitic steel rod (1) gripped and conveyed by a finger (not shown) is moved to a chuck (10a) of a fixed gripper (10).
Similarly, the martensitic steel bar (2) is gripped by the rotary chuck (11a) of the movable gripper (11).

Next, while rotating the rotary chuck (11a) at a high speed, the movable gripper (11) is moved rightward to
If the end surfaces of (1) and (2) are pressed against each other with an appropriate pressure, the pressed surfaces become hot due to frictional heat and are welded to each other to form a material (3). At this time, an annular flash (4) is generated around the joint.

[0008] As shown in FIG.
After the movable gripper (11) moves to the left original position, it is pulled out, and is gripped by the finger.
It is moved to above the punching die (13), lowered vertically and inserted into the punching die (13). The inserted material (3) is held by its burrs (4) being locked in the openings of the die holes of the punching die (13). If the punch (14) is lowered in this state, the burrs (4) are punched out.

[0009]

Conventionally, in the above-described deburring step, deburring was performed by immediately inserting the die into the punching die (13) immediately after pressing. In this case, since the joint between the steel bars (1) and (2) is still in a high temperature state,
Although the removability of (4) is good, the punch (14) strongly presses it in an incomplete bonding state before curing, so that the impact may cause a crack in the bonding portion.

[0010] Since the cracks are minute, it is difficult to find them after the step of punching out the burrs, and they are found in the finishing step of the shaft and the product inspection step, and the steps up to that point are wasted. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a method for removing burrs that can prevent a crack from being generated at a joint between round bar-shaped works.

[0011]

According to the present invention, an object of the present invention is to provide a method in which end faces of a round bar-shaped work are brought into contact with each other, pressed against each other while rotating relative to each other, and then the joined work is inserted into a flash punching apparatus. This is solved by waiting for a predetermined time and then punching out the burrs generated at the joint.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 schematically shows a friction welding apparatus and a burr removing apparatus for a bar-shaped steel material to which the method of the present invention is applied.
The illustration and description are omitted, and the same members as described above are denoted by the same reference numerals and described.

[0013] Above the punching die (13), the material is added to the punching die (13).
When (3) is inserted, a pair of photo sensors (15a) and (15b) for detecting the insertion are provided, and the light receiving unit (15b) is a timer (16).
Is electrically connected to

The timer (16) is connected to a control device (not shown) for controlling the timing of the lowering of the punch (14). After a lapse of a predetermined time (for example, 4 seconds), a signal is issued from the timer (16) to the control device, and the lifting / lowering means is operated to lower the punch (14). By this, the material (3) flash
(4) is punched out.

Therefore, the material (3) immediately after the pressure welding is a punching die (1).
After waiting for a predetermined time in 3), the burrs (4) are punched out after the temperature of the joint (3a) has dropped to a safe temperature, that is, after the joint has been cooled and hardened slightly, so that a crack or the like occurs in the joint (3a). There is no danger of occurrence.

The joining portion (3a) of the material (3) is a chuck (11a)
Since the natural cooling starts from the time when the rotation of the material is stopped, the material (3) after pressing is left for a certain period of time while being held by the chucks (10a) and (11a), and then the burrs (4) are punched out. The same effect as described above can be obtained.

However, since the friction welding apparatus is set so that the joining of one workpiece is completed within a predetermined cycle time, the material (3) after the completion of the welding is chucked to the chuck (1).
Holding at 0a) and (11a) not only hinders gripping of the next work, but also increases the cycle time and lowers productivity. Accordingly, as described above, if the timer (16) is provided on the deburring apparatus side and the timing of punching is slightly delayed, it is possible to keep the work during the pressing of the next work, which may hinder the cycle time. I can't.

The standby time of the blank (13) in the blanking die (13) depends on the size and material of the blank (3) because the cooling rate of the joint (3a) is slightly different. The setting time of 16) may be appropriately changed.

[0019]

According to the method of the present invention, by holding the workpiece after pressing for a predetermined period of time, the bonding strength of the pressing portion becomes appropriate. The incidence of non-defective products is extremely low.

[Brief description of the drawings]

FIG. 1 is a front view of a deburring apparatus to which the present invention is applied when burrs are removed.

FIG. 2 is a front view showing a state in which a workpiece is pressed by a friction welding device.

FIG. 3 is a front view at the time of removing a conventional flash.

FIG. 4 is a front view showing a manufacturing process of the engine valve.

[Explanation of symbols]

 (1) Austenitic steel rod (2) Martensitic steel rod (3) Material (3a) Joint (4) Burr (5) Primary intermediate (6) Secondary intermediate (7) Engine valve ( 8) Base (10) Fixed gripper (10a) Chuck (11) Moving gripper (11a) Rotary chuck (13) Punch type (14) Punch (15a) (15b) Photo sensor (16) Timer

Claims (1)

[Claims] 1. After the end faces of the round bar-shaped workpieces are brought into contact with each other and pressed against each other while rotating relative to each other, the joined workpieces are inserted into a deburring device to stand by for a predetermined time, and then generated at a joint. A method of removing burrs after press-contacting end faces of round bar-shaped workpieces, characterized by punching out burrs.