JPH0676354U - Induction hardening equipment for crankshafts - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] When the load applied to the hardened part during quenching of the crankshaft is constant and the heating coil body is replaced with another type with different weight. , The load applied to the quenched portion of the crankshaft is mechanically controlled within a predetermined range. [Structure] A cylinder 51 having a built-in piston 53 and one end fixed to the piston 53, and a tip portion 5 of the cylinder 51.
Surrounded by a rod 52 having the other end protruding from 1b connected to the upper end of the wire 33, means for detecting the type of heating coil body (dog 81 and limit switch 91), piston 53, rod 52, and cylinder 51. Induction heating of the crankshaft W, which is provided with means (pressure reducing valves 71, 72, 73 and solenoid valves 61, 62, 63) for adjusting the air pressure in the space 54 according to the detected type of heating coil body. Input device.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an induction hardening device for a crankshaft, and more particularly, to an induction hardening device suspended by a linear object of a crankshaft.

[0002]

[Prior art]

 Hereinafter, a conventional technique will be described with reference to the drawings. FIG. 6 is a front view of an example of a crankshaft, FIG. 7 is a front view of a conventional induction hardening device for a crankshaft, and FIG. 8 is a partial view of a heating coil body placed on a portion to be hardened. It is an enlarged front view. A crankshaft W shown in FIG. 6 is a crankshaft for a four-cylinder engine, and includes journals J1 to J5 and pins P1 to P4 that are induction hardened. W1 is a straight line connecting the centers of the journals J1 to J5, and is an axial center line that is the center of rotation of the crankshaft W.

As shown in FIG. 7, a conventional high-frequency quenching apparatus for quenching, for example, a pin P1 of a crankshaft W includes a heating coil 10 such as a half-open saddle type that heats the pin P1 at high frequency, and a heating coil. A pair of quenching liquid jetting jackets 13 and 13 arranged below both sides of the coil 10 to face each other, a lead conductor 11 of the heating coil 10, and an input terminal 14 provided on the upper end of the lead conductor 11. A heating coil body C provided with a pair of coil side plates 12 (front side and back side in FIG. 7) and a transformer T for supplying a high frequency current to the heating coil 10. The heating coil 10, the lead conductor 11, the jacket 13, and the input terminal 14 are attached to the coil side plate 12. Further, the input terminal 14 is connected and fixed to an output terminal 15 protruding from the lower portion of the transformer T so as to be able to come into contact with and separate from it.

To prevent contact between the heating coil 10 and the pin P1 and to keep the gap distance between the heating coil 10 and the pin P1 constant during quenching of the hardened portion of the crankshaft W, for example, the pin P1. In addition, as shown in FIG. 8, a central spacer 17 is provided in the central portion of the heating coil 10 and side spacers 18 are provided on both sides of the heating coil 10. Both the spacers 17 and 18 are fixed to the coil side plate 12 by bolts 16.

In FIG. 7, reference numeral 23 denotes a transformer support member, which includes a horizontal member 23a and a vertical member 23b integrally formed with the horizontal member 23a at an end of the horizontal member 23a. The transformer T is fixed on a base plate 21 suspended from the horizontal member 23a via a pantograph 22. The vertical member 23b is provided with a pair of upper and lower parts slidably fitted on a vertical rail 46 fixed to the front surface of a board 40 called a power matching board for supplying high frequency power to the transformer T. Slide guides 24, 24 are installed.

On the upper surface of the horizontal member 23a of the transformer support member 23, the lower end of the wire 33 wound around the pulley 32 pivotally supported by the tip portion of the stay 31 provided on the upper surface of the board 40 is fixed, The upper end of the wire 33 is connected via a spring 34 to one end of a bolt 35 that is screwed into a protrusion 49 provided on the upper surface of the board 40. A stay 41 is provided on the front surface of the board 40, and a vertical cylinder 42 for moving the rod 43 forward and backward is provided at the tip of the stay 41. The upper end of the rod 43 is in contact with the projection 23c provided on the vertical member 23b of the transformer support member 23.

In addition to the above, a cable tire cable (not shown) that supplies a high-frequency current from the board 40 to the transformer T, a flexible pipe (not shown) that supplies a cooling liquid to the transformer T and the heating coil 10, and The jacket 13 is provided with a flexible pipe (not shown) for supplying the quenching liquid.

In order to quench the pin P1 of the crankshaft W, the crankshaft W is arranged so that the axis W1 is horizontal and the pin P1 is located below the heating coil body C. , The crankshaft W is rotated about the axis W1 to position the pin P1 at the top dead center. Next, when the cylinder 42 is operated to retract the rod 43, the transformer T and the heating coil body C descend from the standby position. Then, the heating coil 10 is placed on the pin P1 which has entered between the pair of jackets 13 and then passed between the jackets 13. Then, when the crankshaft W is rotated, the center of the pin P1 moves on the circumference W2, so that the heating coil body C and the transformer T swing vertically and horizontally.

While rotating the crankshaft W, a high-frequency current is passed from the board 40 through the transformer T to the heating coil 10 for a predetermined time, and then the jacket 13 is quenched while continuing the rotation of the crankshaft W. The liquid is jetted to the pin P1, the pin P1 is cooled, and the quenching of the pin P1 is completed. After that, when the pin P1 reaches the top dead center, the rotation of the crankshaft W is stopped. Next, the cylinder 42 is operated, the rod 43 is advanced, the heating coil body C and the transformer T are raised, and the original standby position is returned. After that, after quenching the pins P2 to P4 in the same manner as the quenching of the pin P1, after replacing the heating coil body C with a heating coil body suitable for quenching the journals J1 to J5, if necessary. , Sequentially quench the journals J1 to J5.

[0010]

[Problems to be solved by the device]

 The above-mentioned conventional induction hardening apparatus for a crankshaft has the following problems. That is, during quenching of the pin P1, which is the portion to be quenched, the load obtained by subtracting the tension of the spring 34 from the total weight of the heating coil body C, the transformer T, and the transformer mounting member 23 is applied to the pin P1. As a result, the pin P1 during quenching revolves so that its center moves on the circumference W2, so that the pin P1 moves up and down.

Therefore, the spring 34 also expands and contracts, and the tension of the spring 34, that is, the tension of the wire 33 also fluctuates so that it becomes minimum at the top dead center of the pin P1 and becomes maximum at the bottom dead center. Therefore, the load applied to pin P1 during quenching is maximum at top dead center and minimum at bottom dead center, but fluctuations in the load applied to the hardened part during quenching of the hardened part such as pin P1 If so, the side spacers 18 are unevenly worn, and the crankshaft W after quenching tends to have a large distortion.

Further, if the load applied to the hardened portion is too large, not only the center spacer 17 and the side spacers 18 are heavily worn, but also the distortion of the crankshaft W after quenching may increase. Therefore, it is necessary to turn the bolt 35 to set the tension of the spring 34 to an appropriate amount to reduce the load applied to the pin P1 during quenching. It is empirically known that it is appropriate that the magnitude of this load is usually within the range of 5 to 10 kg regardless of the size of the crankshaft. For example, when the weight of the heating coil body C is 30 kg, the tension of the spring 34 is set to 20 kg and the weight applied to the hardened portion is set to 10 kg.

However, when the type of crankshaft changes and the size of the hardened part increases, it is necessary to use a large heating coil body, and the weight of the heating coil body inevitably increases. Therefore, it is necessary to readjust the tension of the spring 34. Further, when the weight of the heating coil body is extremely large, adjustment of the tension of the spring 34 cannot handle it, and it is necessary to replace it with a stronger spring. As described above, when replacing the heating coil body corresponding to the type of the crankshaft, it is extremely troublesome to adjust the tension of the spring 34 or replace the vane 34.

The present invention has been made in view of the above circumstances, in which the load applied to the hardened portion during quenching of the crankshaft is substantially constant, and the heating coil bodies have different weights. Crankshaft induction hardening device that can mechanically keep the load applied to the hardened part of the crankshaft within a predetermined range when it is replaced with another type without the need for human intervention. The purpose is to provide.

[0015]

[Means for Solving the Problems]

 In order to solve the above problems, the induction hardening apparatus for a crankshaft according to the present invention comprises a heating coil body mounted on a hardening portion of a crankshaft to heat the hardening portion by induction heating, and a heating coil body. In a crankshaft induction hardening device equipped with a transformer that is detachably attached to the upper part of the coil and supplies high-frequency current to the heating coil body, and a wire rod that suspends this transformer, a cylinder with a built-in piston. A rod to which the piston is fixed at one end and the upper end of the linear object is connected to the other end protruding from the end of the cylinder, means for detecting the type of the heating coil body, the piston, The rod and the means for adjusting the fluid pressure in the space surrounded by the cylinder according to the type of the detected heating coil body are provided.

[0016]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1 to 5 are drawings for explaining the present embodiment, FIG. 1 is a front explanatory view, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 4 is an electric circuit diagram and FIG. 5 is a front explanatory view of each heating coil body. The same components as those described in the related art are designated by the same reference numerals.

The induction hardening apparatus of this embodiment is used, for example, for hardening three kinds of crankshafts by exchanging three kinds of heating coil bodies C1, C2, and C3 having different sizes and weights. can do. As shown in FIG. 5, the structure of the heating coil body C1 is similar to that of the heating coil body C described in the related art, and the heating coil 101, the lead conductor 111, the coil side plate 121, the input terminal 14, and the It has a pair of jackets 131. The heating coil body C2 similarly includes a heating coil 102, a lead conductor 112, a coil side plate 122, an input terminal 14, and a pair of jackets 132. Further, the heating coil body C3 also includes a heating coil 103, a lead conductor 113, a coil side plate 123, an input terminal 14, and a pair of jackets 133. Although not shown, of course, the heating coil bodies C1, C2, and C3 each include a central spacer and side spacers as described in the prior art.

The induction hardening apparatus of the present embodiment is different from the induction hardening apparatus described in the related art only in the points described below, and thus the description of the same portions will be omitted. As shown in FIG. 1, the induction hardening apparatus of this embodiment is provided with a cylinder 51 instead of the panel 34 of the induction hardening apparatus described in the prior art. That is, the cylinder 51 is disposed almost horizontally above the board 40, and the base 51a of the cylinder 51 is rotatably attached to the protrusion 45 provided on the stay 44 fixed to the upper surface of the board 40. ing. A piston 53 is slidably arranged in the cylinder 51.

Reference numeral 52 denotes a linear rod that slidably penetrates the tip end portion 51 b of the piston 51. One end of the rod 52 is fixed to the piston 53, and the other end of the wire 33 is fixed above the wire 33. The ends are connected. Then, into the space 54 surrounded by the piston 53, the rod 52, and the cylinder 51, from the compressed air source 100 via the pipe 201, the pressure reducing valve 71, and the solenoid valve 61, or the pipe 202, the pressure reducing valve 72, Compressed air is supplied either via the solenoid valve 62 or via the pipe 203, the pressure reducing valve 73 and the solenoid valve 63.

The weights of the heating coil bodies C1, C2, and C3 are, for example, 30 kg, 40 kg, and 50 kg, respectively, and the dimensions of the heating coil bodies C1, C2, and C3 are different from each other. The input terminal 14 is formed in the same shape and the same size so that it can be connected to the output terminal 15 of the transformer T. The pressure reducing valve 71 and the solenoid valve 61 correspond to the heating coil body C1, and the pressure reducing valve 72 and the solenoid valve 62 correspond to the heating coil body C2. The pressure reducing valve 73 and the solenoid valve 63 correspond to the heating coil body C3. If the allowable load of the pin P1 during quenching is 10 kg, and the effective pressure receiving area of the piston 53 is, for example, 20 cm ² , the discharge pressure of the pressure reducing valves 71, 72, and 73 is 1 kg / kg, respectively. It is set to cm ² , 1.5 kg / cm ² , and 2 kg / cm ² .

As shown in FIG. 3, dogs 81, 82, and 83 are provided on the side surfaces of the input terminals 14 of the heating coil bodies C1, C2, and C3, respectively. The dogs 81, 82, and 83 are provided at different positions on the side surface of each input terminal 14 for identifying the heating coil body. Contactless limit switches 91, 92, and 93 corresponding to the dogs 81, 82, and 83 are arranged on the lower surface of the base plate 21 to which the transformer T is attached.

As shown in FIG. 4, the limit switch 91 and the solenoid valve 61 are connected in series to the power source 200 through the electric wire 301. Similarly, the limit switch 92 and the solenoid valve 62 are connected in series to the power source 200 via the electric wire 302, and the limit switch 93 and the solenoid valve 63 are also connected in series to the power source 200 via the electric wire 303.

Next, the quenching operation of the crankshaft W by the induction hardening apparatus of this embodiment will be described. First, when the input terminal 14 of the heating coil body C1 is connected to the output terminal 15 of the transformer T, the dog 81 approaches the limit switch 91 so as to face the limit switch 91 and the limit switch 91 operates. As a result, the solenoid valve 61 operates. open. Then, compressed air having a set discharge pressure (1 kg / cm ² ) of the pressure reducing valve 71 is supplied into the space 54 of the cylinder 51, and causes the piston 53 to move toward the base portion 51a of the cylinder 51 at a predetermined constant level. Since the force (20 kg) is always applied, the tension (20 kg) of the wire 33 is always constant.

The hardening operation of the pin P1 is performed in the same manner as in the conventional induction hardening apparatus, but as described above, the piston 53 is always pushed toward the base portion 51a of the cylinder 51 with a constant predetermined force. Therefore, the tension of the wire 33 is always a constant and predetermined value, and the load (10 kg) applied to the pin P1 is always constant even if the pin P1 revolves during quenching and moves up and down. .

When the heating coil body C2 is used for quenching the pin of the crankshaft (not shown) different from the crankshaft W by changing the type of the crankshaft, the transformer T of the heating coil body C1 is used. And the solenoid valve 61 is closed. Next, when the input terminal 14 of the heating coil body C2 is connected to the output terminal 15 of the transformer T, the dog 82 of the heating coil body C2 operates the limit switch 92 to open the solenoid valve 62 and set the pressure reducing valve 72. Compressed air with a different discharge pressure is supplied into the space 54 of the cylinder 51, and the piston 53 is directed toward the base 51a of the cylinder 51 with a force of a certain magnitude larger than when the heating coil body C1 is used. Since the wire 33 is always pushed, the tension of the wire 33 is also kept constant and the load applied to this pin during quenching is constant. The same applies when quenching a crankshaft of a different type, for example, a pin using the heating coil body C3.

In the above embodiment, the case of quenching the pin of the crankshaft W has been described as an example. However, when quenching the journal, the induction coil of this embodiment is used even though the heating coil body does not move up and down. An input device can be used. Further, in the above-mentioned embodiment, the case where the heating coil body also injects the quenching liquid has been described, but it is also possible to use it only for heating without wearing the jacket or without injecting the quenching liquid from the jacket. Further, in the above embodiment, the wire 33 wound around the pulley 32 was used as the filament, but the wire 33 is not limited to this and may be a chain wound around a sprocket.

[0027]

[Effect of device]

 As described above, according to the present invention, the heating coil body is placed on the hardened portion of the crankshaft to heat the hardened portion by high frequency, and the heating coil body is detachably attached to the upper portion of the heating coil body. In a crankshaft induction hardening device equipped with a transformer that supplies high-frequency current to the heating coil body and a wire rod that suspends this transformer, a cylinder with a built-in piston and a piston fixed at one end The rod to which the upper end of the filament is connected to the other end protruding from the end of the cylinder, the means for detecting the type of heating coil body, and the fluid pressure in the space surrounded by the piston, rod, and cylinder. And means for adjusting according to the detected type of the heating coil body.

Therefore, in the induction hardening apparatus for a crankshaft of the present invention, the pressure of the fluid in the space surrounded by the piston, the rod and the cylinder is mechanically adjusted according to the weight of the heating coil body to be used. The fluid pressure in the space is always kept at a regulated pressure. Therefore, since the fluid pressure applied to the piston, that is, the tension of the linear object is always constant, a constant load is always applied to the hardened portion during quenching of the hardened portion. Therefore, uneven wear of the spacers can be prevented, and the distortion of the crankshaft after quenching can be reduced.

Further, when the heating coil body is replaced with another type, as described above, the fluid pressure in the space, and hence the tension of the filamentous material, corresponds to the exchanged heating coil body. Since the tension changes mechanically, the time required for adjusting the tension of the spring or the time required for replacing the spring becomes unnecessary, and the quenching time of the crankshaft can be shortened.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a partial perspective view of a heating coil body according to an embodiment of the present invention.

FIG. 4 is an electric circuit diagram of an embodiment of the present invention.

FIG. 5 is a front explanatory view of each heating coil body according to an embodiment of the present invention.

FIG. 6 is a front view of an example of a crankshaft.

FIG. 7 is a front explanatory view of a conventional induction hardening apparatus for a crankshaft.

FIG. 8 is an enlarged front view of a part of the heating coil body in a state where the heating coil body is placed on a portion to be hardened.

[Explanation of symbols]

 33 Wire 51 Cylinder 52 Rod 53 Piston 61, 62, 63 Solenoid valve 71, 72, 73 Pressure reducing valve 81, 82, 83 Dog 91, 92, 93 Limit switch C1, C2, C3 Heating coil body P1 to P4 Pin J1 to J5 Journal T Transformer W Crankshaft

Claims (1)

[Scope of utility model registration request] 1. A heating coil body mounted on a quenching portion of a crankshaft for heating a quenching portion by high frequency, and a heating coil body which is detachably attached to an upper portion of the heating coil body and is applied to the heating coil body with a high frequency current. In an induction hardening apparatus for a crankshaft, which comprises a transformer for supplying a coil and a linear object suspending the transformer, a cylinder having a built-in piston, the piston being fixed at one end, and an end portion of the cylinder A rod whose upper end is connected to the upper end of the linear object, a means for detecting the type of heating coil body, and a heating coil in which the fluid pressure in the space surrounded by the piston, rod, and cylinder is detected. An induction hardening device for a crankshaft, comprising: a means for adjusting according to the type of body;