JPH0120212B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is applicable when both ends of a shaft-like object have a predetermined length of a portion that does not require heating, or conversely, when the central portion is a portion that does not require heating and a predetermined length at both ends is a portion that requires heating. The present invention relates to a continuous induction heating device for a shaft-like object that has a part that does not need to be heated, and is capable of heating only the part that requires heating while continuously feeding the shaft-like object.

For example, in order to ensure that there is no problem in threading each end of a shaft-shaped object in the subsequent process, the first conventional device is used to perform heat treatment such as hardening only on the central part, excluding a predetermined length of both ends. The ones shown in Figures a and b are used.

In Fig. 1a, W is a shaft-like object having a length L, and the length l at both ends of the shaft-like object W is a part Wa that does not require hardening, and the central part with a length q shown as Wb is a part that requires hardening. Department.

C is an induction heating coil (hereinafter referred to as a coil) to which a cooling mechanism is added, and on the left and right sides of the coil C, there is a rotating roller group 10 consisting of a plurality of pairs of rotating rollers connected in the axial direction. , 10 are provided to constitute a transport path for the shaft-like object W. The above-mentioned pairs of rotating rollers are arranged so that the rotating rollers shown as 11 and 11 in FIG. If the shaft-like object W is placed on the shaft-like object W, it is possible to cause the shaft-like object W to rotate in a direction opposite to the rotation direction of the rotating roller 11.

Reference numeral 20 denotes a presser provided, for example, at the tip of the rod 21 of the cylinder 22;
is set to be able to move forward and backward in the left and right directions as shown by the arrows, and moves forward at predetermined time intervals to reach the left end of the shaft-like object W that is sent onto the transfer path 10 by a feeder (not shown). After contacting the surface, the shaft-like object W is pressed and pushed to the right by a predetermined distance = length L of the shaft-like object W.

The distance between the coil C and the most advanced position of the presser 20 is determined by the sum of the lengths (n×L) of the plurality of shaft-like objects W and the length l of the non-quenched part of one end of the shaft-like objects W. Set. Therefore, the pusher 20 moves forward n times.
When the backward movement is performed, the tip of the first shaft-like object W is pushed by the succeeding shaft-like objects W that are sequentially supplied, and is moved to a transfer path 10 separated by a length l from the front surface of the coil C.
While reaching the upper position, the shaft-like object W is being rotated by the rotating roller 11.

S ₁ and S ₂ are detectors made of, for example, micro switches, etc., and detector S ₂ is provided at the most advanced position of the presser 20, and detector S ₁ is located to the left of the detector S ₂ . They are provided at intervals corresponding to the length q of the hardened portion Wb of the shaft-like object W.
Each of the detectors S ₁ and S ₂ detects that the presser 20 has moved forward to the installation position of the detectors S ₁ and S ₂ when the presser 20 moves forward, and outputs a detection signal to the switch 32 . Thus, the switch 32 is set to close the power source 31 of the coil C by the output of the detector S ₁ , and to open the power source 31 by the output of the detector S ₂ .

Therefore, if the forward speed of the presser 20 by the cylinder 22 is set to a predetermined value, the n+1st shaft-shaped object W supplied from the feeder onto the transfer path 10
As the pusher 20 moves forward and pushes, the most advanced shaft-shaped object W moves forward and enters the coil C, and when the pusher 20 reaches the position of the detector _S1 , the coil Power is started from the power supply 31 to C,
Then, when the presser 20 further advances a distance equivalent to q and reaches the position of the detector _S2 , the power supply from the power source 31 is stopped. Therefore, the hardening required portion Wb of the shaft-like object W passing through the coil C while rotating on the transfer path 10 and being pushed at a predetermined feed rate is hardened. Since the forward movement of the presser 20 is stopped when the hardening of the part Wb that requires hardening is completed,
The portion Wa that does not require hardening at the rear of the shaft-like object W in the feeding direction is still located in front of the coil C. However, the presser 20 moves backward in the next operation, and then the next shaft-like object W
is fed onto the transfer path 10 by the feeder, and when the presser 20 starts moving forward again, the most advanced shaft-like object W
is pushed by the subsequent shaft-like object W, so that the part Wa that does not require rear hardening passes through the inside of the coil C. At the same time, the following shaft-shaped object W moves forward into the coil C, and at the point when its advancement has progressed to a distance equivalent to l, the detector S ₁
detects the presser 20 and outputs a detection signal, so energization is started in the same manner as above, and the hardening of the portion Wb that requires hardening is performed intermittently as the presser 20 moves forward and backward repeatedly. It is starting to be done.

Since the above-mentioned conventional device performs intermittent feeding by the presser 20 driven by the cylinder 22, in addition to the forward movement time of the presser 20, which is directly related to heating or quenching, the retracting time of the presser 20 and the transfer path from the feeder. However, no matter how well the design is carried out,
The average feed speed, that is, the processing speed is, for example, diameter; 20 mm.
In the case of a shaft-like object W with φ, length L: 300 mm, and length l of parts Wa that do not require quenching at both ends: 15 mm, it was difficult to achieve a speed of 30 mm/sec or more.

In addition, there is another conventional continuous induction heating device that performs one-shot heating using a coil C whose length corresponds to the length of the part Wb that requires hardening, but this device not only requires intermittent feeding cycle time, but also requires intermittent feed cycle time. , since the coil C becomes large, the power output must also be large, resulting in a larger device and more expensive equipment, which has even more drawbacks than the former.

The present invention was made in order to eliminate the above-mentioned drawbacks of the conventional products.In addition to being able to increase productivity by almost twice as much as the conventional products, the present invention also requires a smaller coil. The purpose of the present invention is to provide a continuous induction heating device for objects.

The gist of the first invention of the present application is to provide a transfer path for continuously feeding a shaft-like object in a column at a predetermined speed, the end portions of which have predetermined lengths that do not require heating. n + length of one of the above heating-free parts)
an induction heating coil disposed at a position separated by a distance corresponding to , a rapid loading device connected to the loading end side of the transfer path, and a rear end of a shaft-like object passing through the loading end. a rear end detector that sends an energization stop command signal to the power supply circuit of the induction heating coil; and a signal generator that outputs an energization start command signal to the power supply circuit after the shaft-like object has moved a predetermined distance from the generation of the energization stop command signal. A continuous induction heating device for a shaft-like object having a part that does not need to be heated, characterized in that the predetermined distance corresponds to the sum of the lengths of the part that does not need to be heated plus the width of the induction heating coil. .

The present invention will be described below with reference to an embodiment shown in FIG. Note that the explanation is for hardening.

In FIG. 2, reference numeral 61 denotes a feeding device, which is comprised of, for example, a caterpillar conveyor disposed facing each other in the vertical direction, and is rearward in the feeding direction of a rotating roller group 62, which has the same configuration as 10 in FIG. 1 showing the conventional device. end 6
A shaft-shaped object W of length L that is connected to 2a and fed in
is sent out to the rotating roller group 62 at a predetermined feed speed of _V1 . The feeding device 61 and the rotating roller group 62 constitute a transporting path 60 for the shaft-like object W, and the transporting end 60a thereof
A distance corresponding to the side direction distance (nL+l) from the delivery end 60b, that is, the sum of the length of n shaft-like objects of length L and the length l of the non-quenched part, and the width is α.
A coil C is disposed with its inlet end face positioned. Since this embodiment is a quenching device, a cooling liquid injection device is added to the coil C.
The above α means the width of the heating conductor of the coil C.

Reference numeral 70 denotes a rapid loading device, which includes a constantly operating conveyor 71 connected to the loading end side of the feeding device 61 and a shutter 72 installed on the shipping side of the conveyor 71. The feed speed V ₂ of the conveyor 71 is set to be V ₂ >V ₁ in relation to the feed speed V ₁ of the feed device 61, and the shutter 72 is closed and the shaft-shaped object W is kept on the conveyor 71. The shaft-shaped object W is rapidly carried into the feeding device 61 by the opening operation.

Reference numeral 80 denotes a rear end detector of the shaft-like object W, which is provided at the carry-in end 60a of the transfer path 60, and outputs P ₁ when the rear end of the shaft-like object W carried into the transfer path 60 passes through the carry-in end 60a. It is configured to do this. This output P ₁
serves as a energization stop command signal to open the switch 32 of the power source 31, and at the same time, the rapid loading device 70
This serves as a carry-in command signal for opening the shutter 72 for a predetermined period of time, and is also sent to a signal generator to be described later. As the rear end detector 80, for example, a micro switch, a phototube, or the like is used.

Reference numeral 90 is a signal generator, for example, a timer, to which the output P ₁ of the rear end detector 80 is input, and when a time T; [(2l+α)/V ₁ ] has elapsed after the output P ₁ was generated,
In other words, the shaft-shaped object W pushed by the feeding device 61 at a moving speed V ₁ is moved to the non-quenching portion Wa at both ends.
When the coil moves forward by a distance corresponding to the sum of the lengths l plus the width α of the coil C, an output P ₂ is generated.
This output P ₂ becomes an energization start command signal for closing the switch 32 of the power source 31.

Next, the operation of this device will be explained.

Each of the shaft-like objects W sequentially carried into the transfer path 60 is pushed by the following shaft-like object W and continuously moves at a predetermined speed _V1 while forming a column on the side of the delivery end 60b.

FIG. 2 shows that the (n+1)th shaft-like object Wn+1 is carried into the transfer path 60, the rear end of the shaft-like object Wn+1 reaches the carry-in end 60a, and
The part that does not require hardening on the rear side of the shaft-like object _W1 brought into
The figure shows a state in which Wa has reached the inlet end face of the coil C.

When the rear end of the (n+1)th shaft-like object Wn+1 reaches the carry-in end 60a, the rear end detector 80 outputs an output and the energization of the coil C is stopped. At the same time, the shutter 72 opens, and the (n+2)th shaft-like object Wn that has already been transferred and placed on the rapid loading device 70
+2 is carried into the transfer path 60. Rapid loading device 70
The carrying-in speed V ₂ of passed the carrying-in end 60a (n+
1) Since the moving speed of the second shaft-like object Wn+1 is greater than V ₁ , the carried-in shaft-like object Wn+2 immediately follows the preceding shaft-like object Wn+1 and moves to the feeding device 61.
is sent toward the sending end 60b at a moving speed _V1 . In this feeding process, the unnecessary hardening part Wa on the rear end side of the first shaft-like object W ₁ and the unnecessary hardening part Wa on the front end side of the succeeding shaft-like object W ₂ are separated from the coil C.
However, since the current supply to the coil C is stopped, heating and hardening are not performed.

When the shaft-shaped object _W2 moves forward, a time T has elapsed since the output of the rear end detector 80 is generated, that is, the advancing distance is (2l+α).
When the length corresponds to the length, the signal generator 90 outputs an output and closes the switch 32 of the power source 31, so that energization of the coil C is started. In this state,
Since the tip of the part Wb that requires hardening of the shaft-like object _W2 has reached the inside of the coil C, the moving hardening process is started for the part Wb that requires hardening at the feed rate _V1 .

As described above, while the moving hardening process for the shaft-like object _W2 continues, on the other hand, the movement of the shaft-like object Wn+2 carried into the feeding device 61 also continues.
The rear end of the shaft-like object Wn+2 will eventually become the carry-in end 60a.
, and trailing edge detector 80 generates an output P ₁ .
Accordingly, the power supply 31 is opened, and the shaft-like object W ₂
The hardening process for the hardening required portion Wb is completed.

Thereafter, the above-mentioned operations are repeated, and each shaft-like object W carried into the transfer path 60 is continuously moved, and the portions Wb excluding the portions Wa that do not require quenching are sequentially hardened.

With the device having the above configuration, the length L mentioned above can be
When processing a 300 mm shaft member, even if the moving speed of the shaft member is the same as before, the time required for the conventional device to retreat the presser 20 and the time for placing it from the feeder onto the transfer path 10 is saved. It became possible to increase the processing speed to 60mm/sec.

Although the above embodiment has been described as a case of hardening, it is of course applicable to, for example, a case of tempering heating.

Further, in the above embodiment, the rear end detector 80 is arranged at the carry-in end 60a of the transfer path 60, but the arrangement position is not limited to this. That is, in order to adjust the arrangement position of the rear end detector 80 to (nL+l) due to the relationship between the length L of the shaft-like object W and the length l of the non-heating part Wa, it is necessary to move the rear end detector 80 from the carry-in end 60a to the delivery end 60b side. It is only necessary to place them a predetermined distance from each other. In this case, the arrangement position of the rear end detector 80 becomes the substantial carry-in end 60a.

In the above embodiment, a timer is used as the signal generator 90, but instead of the timer, for example, a second A rear end detector may be provided, and the switch 32 of the power source 31 may be closed by the output of the second rear end detector. Furthermore, a speed detector that detects the moving speed of the shaft-like object W is used, and when the moving distance of the shaft-like object W reaches a predetermined value based on the product of the detected speed and time, an output is output and the switch of the power source 31 is activated. 32 may be configured to be closed.

The second invention of the present application is, contrary to the first invention described above, which targets a shaft member W having non-heating parts Wa at both ends,
For example, a predetermined length l at both ends is a sliding part that requires heating due to the need to form a hardened layer.
Wb, and the shaft member W whose center portion is a heating-free portion Wa is targeted.

The second invention differs from the first invention in that the energization start and energization stop operations are completely reversed, but the other configurations are the same as the first invention. However, since the coil C has a width α, specifically, the distance between the rear end detector 80 and the induction heating coil is subtracted by the width α of the coil C from the case of the first invention (nL
+l-α), and the predetermined distance that the shaft-shaped object W moves from the generation of the output of the rear end detector 80 to the output from the signal generator 90 is set to the width α of the coil C, contrary to the case of the first invention. The basic principle is the same as the first invention, although it is necessary to consider that the length is equivalent to (2l-α) after subtracting the length.

In this case, it goes without saying that the relationship between the width α of the coil C and the length of the portion to be heated l must satisfy α≦l.

As described above, the present invention has the effect of continuously moving the shaft-like object on the transfer path without stopping it at all, and heating only the parts that need heating, which reduces the retraction time of the presser and the time required to carry the shaft-like object in the conventional device. Since no time is required, processing speed can be greatly increased, and production efficiency can be almost doubled. Furthermore, there is no need to increase the width of the coil to match the length of the heating section as in other conventional examples, and there is no need for an expensive large power supply, so equipment investment can be kept at low cost. The effect is remarkable.

[Brief explanation of drawings]

FIG. 1 is a front view of a conventional induction heating device, and FIG. 2 is a front view of an embodiment of a continuous induction heating device according to the present invention. W... Shaft-like object, Wa... Heating-unnecessary part, L... Shaft-like object total length, l... First invention: Length of unnecessary heating part, Second invention: Length of heating-necessary part, C... Induction heating coil,
α... Width of induction heating coil, 60... Transfer path, 6
0a... Carrying-in end, 60b... Sending-out end, 70... Rapid carrying-in device, 80... Rear end detector, 90... Signal generator.

Claims (1)

[Scope of Claims] 1. A transfer path for continuously feeding shaft-like objects in tandem at a predetermined speed, both ends of which have predetermined lengths that do not require heating; An induction heating coil disposed at a distance corresponding to the length of one side of the non-heating portion, a rapid loading device connected to the loading end side of the transfer path, and passing through the loading end. A rear end detector detects the rear end of the shaft-like object and sends a energization stop command signal to the power supply circuit of the induction heating coil, and starts energization after the shaft-like object moves a predetermined distance from the generation of the energization stop command signal. There is a part that does not need to be heated, comprising a signal generator that outputs a command signal to a power supply circuit, and the predetermined distance corresponds to the sum of the lengths of the part that does not need to be heated plus the width of an induction heating coil. Continuous induction heating device for shaft-like objects. 2. A transfer path for continuously feeding shaft-like objects in tandem at a predetermined speed, with the central part being a part that does not require heating and the predetermined lengths at both ends being heating-required parts; An induction heating coil disposed at a distance corresponding to n + length of one side of the above-mentioned heating section - width of the induction heating coil), and a rapid carry-in coil arranged in series on the carry-in end side of the transfer path. a device, a rear end detector that detects the rear end of the shaft-shaped object passing through the carry-in end and sends a energization start command signal to the power supply circuit of the induction heating coil; It is characterized in that it is equipped with a signal generator that outputs an energization stop command signal to the power supply circuit after moving a predetermined distance, and the predetermined distance corresponds to the sum of the lengths of the parts requiring heating minus the width of the induction heating coil. Continuous induction heating device for shaft-like objects with parts that do not require heating.