JP6485806B2 - Pusher unit for continuous heat treatment furnace, continuous heat treatment furnace, and continuous heat treatment method - Google Patents

Description

  The present invention relates to a pusher unit for a continuous heat treatment furnace that performs a carburizing process or the like.

  As a heat treatment furnace for performing a carburizing process or the like of a workpiece, there is a continuous heat treatment furnace as in Patent Document 1. The continuous heat treatment furnace of Patent Document 1 includes a cylindrical pusher rod provided so as to penetrate the furnace wall. A claw (engagement portion) is provided on the outer peripheral surface of the pusher rod so as to protrude outward from the pusher rod. A plurality of claws are provided at predetermined intervals along the direction of expansion and contraction of the pusher rod. The pusher rod is configured to be rotatable in the circumferential direction.

  In such a continuous heat treatment furnace using a pusher rod, a claw of the pusher rod is applied to a tray on which the workpiece is placed, and the workpiece is moved by moving the pusher rod forward or backward in that state. For this reason, during the operation of the furnace, the forward movement, backward movement and rotation of the pusher rod are repeated.

  The pusher rod may hang down due to thermal deformation. On the other hand, conventionally, a rod cradle 51 for supporting a pusher rod 50 as shown in FIG. 1 has been provided. The rod cradle 51 includes a support roller 52 having a rotation axis perpendicular to the rotation axis of the pusher rod 50. Thus, the forward and backward movement of the pusher rod 50 is not hindered while supporting the tip of the pusher rod 50.

JP2012-63128A

  Since the support roller of the rod cradle is in point contact with the pusher rod, the contact portion between the support roller and the pusher rod is worn when the pusher rod moves forward and backward and when it rotates. Further, as shown in FIG. 2, when the pusher rod 50 rotates, the pusher rod 50 may be displaced along the rotation axis direction of the support roller 52. When the pusher rod 50 moves forward or backward in a state where such a lateral displacement occurs, the pusher rod 50 tries to return to the initial position by rubbing the surface of the support roller 52. Thereby, the surface of the support roller 52 is easily worn. Further, when the lateral displacement of the pusher rod 50 increases, the wear range (shaded portion in FIG. 2) also increases. For this reason, the replacement frequency of the support roller 52 is also increased.

  Further, if the pusher rod is moved forward and backward in a state where lateral displacement has occurred, there is a concern that the tray cannot be moved straight along the transport direction. Further, when the wear range is expanded due to lateral displacement, irregularities are formed on the surface of the support roller, and the position accuracy of the pusher rod placed on the support roller is lowered.

  This invention is made | formed in view of the said situation, and it aims at suppressing the drooping of the front-end | tip part by the thermal deformation of the pusher rod used for a continuous heat processing furnace, and a lateral shift.

  The present invention for solving the above-mentioned problems is a pusher unit used in a continuous heat treatment furnace for heat-treating a workpiece, comprising a pusher rod having a circular longitudinal cross-sectional shape, and a plan view with respect to the rotation axis of the pusher rod. A support roller having a vertical rotation axis and a side roller having a rotation axis parallel to the rotation axis of the pusher rod, and the side roller can be contacted when the pusher rod rotates. It is characterized by being provided.

  In the pusher unit according to the present invention, since the side roller is provided, the pusher rod comes into contact with the side roller even if a lateral displacement occurs in the pusher rod. At this time, the side roller rotates in such a direction as to push back the pusher rod. As a result, the pusher rod is returned to the vicinity of the initial position, and the lateral displacement of the pusher rod can be suppressed.

  Another aspect of the present invention is a continuous heat treatment furnace for heat-treating a workpiece, and is characterized by including the above-described continuous heat treatment furnace pusher unit.

  According to still another aspect of the present invention, there is provided a continuous heat treatment method for heat-treating a workpiece, wherein when the pusher rod included in the pusher unit is rotated using the pusher unit for the continuous heat treatment furnace, the pusher rod is rotated. Is rotated in a first rotation direction by a first angle, and then is rotated in a second rotation direction opposite to the first rotation direction by a second angle smaller than the first angle. It is a feature.

  According to the present invention, lateral displacement of a pusher rod used in a continuous heat treatment furnace can be suppressed. Thereby, while being able to make the wear range of a support roller small, the fall of the position accuracy of a pusher rod can also be prevented.

It is a figure which shows schematic structure of the conventional rod cradle. It is a figure which shows the state at the time of rotation of a pusher rod at the time of using the conventional rod cradle. It is a cross-sectional view showing a schematic configuration of a continuous heat treatment furnace according to an embodiment of the present invention. In addition, in order to make it easy to see the configuration of the pusher rod and the rod pedestal, a partial configuration of the furnace is indicated by a broken line. It is the side view seen from the tip side of a pusher rod which shows a claw part of a pusher rod concerning an embodiment of the present invention. It is a top view which shows schematic structure of the rod cradle which concerns on embodiment of this invention. It is a front view which shows schematic structure of the rod cradle which concerns on embodiment of this invention. It is the side view seen from the tip side of a pusher rod which shows schematic structure of a rod cradle concerning an embodiment of the present invention. It is a figure which shows the state at the time of rotation of a pusher rod at the time of using the rod cradle which concerns on embodiment of this invention.

  Hereinafter, a pusher unit according to an embodiment of the present invention will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

  The pusher unit 1 according to this embodiment is used in a continuous heat treatment furnace as shown in FIG. The continuous heat treatment furnace of the present embodiment is a continuous carburizing furnace 10 that performs a carburizing and quenching process on the workpiece W.

  The continuous carburizing furnace 10 according to the present embodiment includes a folded portion R in which the conveyance direction T of the workpiece W changes 180 degrees in the middle of the furnace. A plurality of partition doors 11 are provided in the middle of the transport path, and a region surrounded by each partition door 11 serves as a processing chamber for performing a predetermined process on the workpiece W. The continuous carburizing furnace 10 according to the present embodiment includes, in order along the transport direction T, a first heating chamber 12, a second heating chamber 13, a first carburizing chamber 14, a second carburizing chamber 15, a third carburizing chamber 16, A diffusion chamber 17, a descending greenhouse 18, and a quenching chamber 19 are provided. The first heating chamber 12 is provided with a carry-in entrance 20 into which a work W placed on a tray (not shown) is carried, and the work W is carried in from the lower side of the furnace by a lifting lift 21.

  The pusher unit 1 that transports the workpiece W includes a pusher rod 2 that extends along the transport direction T, a drive mechanism 3 that expands and contracts along the transport direction T and rotates the pusher rod 2 in the circumferential direction, and the operation of the drive mechanism 3. A control device 30 for controlling is provided. In this embodiment, three pusher units are provided. Specifically, the first pusher unit 1a that pulls and conveys the workpiece W from the first temperature raising chamber 12 to the second carburizing chamber 15, and the second pusher unit that pushes and conveys the workpiece W from the third carburizing chamber 16 to the quenching chamber 19. 1 b, a third pusher unit 40 that pushes and conveys the workpiece W from the second carburizing chamber 15 to the third carburizing chamber 16.

  In the present embodiment, the first pusher unit 1a and the second pusher unit 1b have substantially the same configuration. Therefore, in the following description, the first pusher unit 1a (hereinafter referred to as “pusher unit 1”). As an example, the configuration will be described. Since the third pusher unit 40 has a well-known configuration, description thereof is omitted.

  As shown in FIG. 4, the pusher rod 2 is formed so that the longitudinal cross-sectional shape (vertical cross-sectional shape orthogonal to the expansion and contraction direction of the rod) is circular. A plurality of claws 2 a protruding outward from the pusher rod 2 are provided on the outer peripheral surface of the pusher rod 2. The pusher rod 2 is provided below the work W to be conveyed, and is configured to rotate by a drive mechanism 3 (FIG. 3). The pusher rod 2 is formed of, for example, SUS310S.

As shown in FIG. 3, the pusher unit 1 includes two rod receiving bases 4 that support the pusher rod 2, and each rod receiving base 4 is provided below the pusher rod 2. As shown in FIGS. 5 to 7, on the upper surface of each rod cradle 4, the support roller 5 is provided with a vertical axis of rotation A _R in plan view with respect to the rotation axis A _P of the pusher rod 2 . The support roller 5 is disposed in contact with the lower part of the pusher rod 2 and supports the pusher rod 2 from below.

Further, as shown in FIGS. 5 to 7, on the upper surface of each rod cradle 4, and two side rollers 6 having parallel rotation axes A _S with respect to the rotation axis A _P of the pusher rod 2 is provided Yes. Each side roller 6 is disposed below the pusher rod 2 and behind the support roller 5 (the rear end side of the pusher rod 2). Moreover, as shown in FIG. 5, each side roller 6 is arrange | positioned so that it may mutually oppose in planar view, and is arrange | positioned by the positional relationship that the pusher rod 2 exists between this pair of side rollers. .

  In the present embodiment, the side rollers 6 and the pusher rod 2 at the initial position are arranged at intervals so as not to contact each other. In addition, the space | interval between side rollers is suitably determined according to the diameter and material of the pusher rod 2, the material of the support roller 5 or the diameter and material of the side roller 6, and the amount of lateral displacement of the pusher rod 2 to be suppressed. . Moreover, the side roller 6 should just be provided so that the pusher rod 2 and the side roller 6 can contact between the rotation start of the pusher rod 2 and the completion | finish of rotation. If the pusher rod 2 comes into contact with the side roller 6 even once before completing the rotating operation, it is possible to obtain a lateral displacement suppressing effect of the pusher rod 2 described later.

As shown in FIG. 3, in the present embodiment, of the two rod cradle 4 provided in the pusher unit 1, the side roller 6 of the first rod cradle 4 a located on the distal end side of the pusher rod 2. the distance D _1, spacing D ₂ of the side rollers 6 of the second rod cradle 4b located on the rear end side of the pusher rod 2 are different. Specifically, the interval D ₂ is narrower than the spacing D _1.

  As shown in FIGS. 5 and 6, the both ends of the side roller 6 are tapered. For this reason, the roll outer diameter of the both ends of the side roller 6 is smaller than the roll outer diameter of the center part of the side roller 6. This prevents the pusher rod 2 from contacting the side surface 6 a of the side roller 6 when the pusher rod 2 moves forward.

  Further, hard coating is applied to the surfaces of the support roller 5 and the side roller 6. In this embodiment, Stellite No. 6 is sprayed on the surfaces of the support roller 5 and the side roller 6. Thereby, while being able to reduce the friction coefficient of the surface of the support roller 5 and the side roller 6, it can aim at the improvement of abrasion resistance. As a result, the replacement frequency of the support roller 5 and the side roller 6 can be reduced. In addition, the support roller 5 and the side roller 6 are formed by SUS310S etc., for example.

  The pusher unit 1 according to the present embodiment is configured as described above. When the workpiece W is transported by the pusher unit 1 configured as described above, first, the pusher rod 2 is advanced with the claws 2a placed horizontally. Thereafter, the pusher rod 2 is rotated 90 degrees, and the pusher rod 2 is moved backward. Thereby, the nail | claw 2a and the tray (not shown) in which the workpiece | work W was mounted contacted, and the workpiece | work W can be conveyed along the conveyance direction T. FIG. Then, after the workpiece W is moved by one room, the pusher rod 2 is moved forward with the claw 2a laid again. By repeating such an operation, subsequent workpieces W are successively conveyed.

  When the pusher rod 2 rotates in the course of this transport operation, the pusher rod 2 moves so as to roll along the direction of the rotation axis of the support roller 5 as shown by the broken line in FIG. If it does so, the pusher rod 2 will contact the side roller 6 arrange | positioned so that the pusher rod 2 may be inserted | pinched. At this time, the side roller 6 is rotated in such a direction as to return the pusher rod 2 to the initial position by the elastic force of the pusher rod 2. Thereby, the pusher rod 2 is returned to the vicinity of the initial position, and the lateral displacement of the pusher rod 2 can be suppressed.

  That is, according to the pusher unit 1 according to the present embodiment, the lateral displacement of the pusher rod 2 can be suppressed by providing the side roller 6. For this reason, the pusher rod 2 always exists in the vicinity of the initial position, and the movement of the pusher rod 2 that rubs the surface of the support roller 5 is reduced. Thereby, the wear range of the support roller 5 can be reduced and the wear amount is also reduced. As a result, the replacement frequency of the support roller 5 can be reduced. Further, the positional accuracy of the pusher rod 2 can be improved.

  Note that the elastic force of the pusher rod 2 when the pusher rod 2 rotates is smaller as it approaches the tip of the pusher rod 2, and the pusher rod 2 tends to be bent like a bow when the pusher rod 2 rotates. For this reason, even if the rotated pusher rod 2 contacts the side roller disposed at a position close to the tip of the pusher rod 2, the side roller is difficult to rotate because the elastic force of the pusher rod 2 is small. Accordingly, there is a concern that the pusher rod 2 does not return to the vicinity of the initial position and gets over the side roller. In this case, it is conceivable to widen the distance between the side rollers, but if so, the effect of suppressing the lateral displacement of the pusher rod 2 may be reduced.

  Therefore, it is preferable to arrange the side roller closer to the rear end of the pusher rod 2 (for example, the rear end side than the position of 1/2 of the entire length of the furnace). Thereby, when the pusher rod 2 rotates, the vicinity of the rear end of the pusher rod 2 having a large elastic force comes into contact with the side roller, so that the side roller is easy to rotate, and the pusher rod 2 can be returned to the vicinity of the initial position more reliably. it can.

Also, as in the present embodiment, if narrow side rollers spacing D ₂ of the second rod cradle 4b than the side roller spacing D ₁ of the first rod cradle 4a, the pusher rod 2 to bend arched The side roller 6 can be brought into contact with the shape. Thereby, each side roller 6 arrange | positioned at the 1st rod receiving stand 4a and the 2nd rod receiving stand 4b becomes easy to rotate, and the effect which suppresses the lateral displacement of the pusher rod 2 can be heightened.

  As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to this example. It is obvious for those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea described in the claims. It is understood that it belongs to.

For example, in the above embodiment, two side rollers 6 are provided in each of the second heating chamber 13 and the descending chamber 18, but the number and arrangement of the side rollers 6 are not limited to this, and the structure of the furnace and the pusher rod It is determined appropriately according to the length of 2. For example, the side rollers 6 may not be arranged so as to face each other. In plan view, be arranged in a positional relationship such as the rotation axis A _P of the pusher rod 2 is present between the rotation axis A _S of the side rollers 6, also have different longitudinal position of the side rollers 6 The lateral displacement of the pusher rod 2 can be suppressed. Further, the side roller 6 may be provided only on one side, not on both sides of the pusher rod 2. Even in this case, if the pusher rod 2 is controlled to rotate in the direction in which the side rollers 6 are arranged, lateral displacement of the pusher rod 2 can be suppressed. In the above embodiment, the support roller 5 is provided in front of the side roller 6, but the support roller 5 may be provided behind the side roller 6. Further, the side roller 6 may be disposed in a different processing chamber from the support roller 5.

  In the above embodiment, both end portions of the side roller 6 are tapered. However, at least the rear end portion (the two ends of the side roller 6 are relatively roots of the pusher rod 2). It is only necessary to be applied to the end near the side. Thereby, contact with pusher rod 2 and side roller side 6a can be avoided. Further, the hard coating on the roller surface may be applied only to either the support roller 5 or the side roller 6.

  In addition, when the pusher rod 2 rotates, the control device 30 performs the first rotation control that rotates the pusher rod 2 in the first rotation direction by the first angle, and then reverses the first rotation direction. The second rotation control for rotating the second rotation direction by a second angle smaller than the first angle is performed, the first rotation control and the second rotation control are repeatedly performed, and the pusher rod 2 is moved to the target angle. It may be configured to rotate up to. For example, when the pusher rod 2 is rotated 180 degrees, the pusher rod 2 may be rotated 70 degrees clockwise and then rotated 10 degrees counterclockwise three times. As described above, when the pusher rod 2 is rotated, the pusher rod 2 is not rotated to the target angle by one rotation, but is rotated stepwise to the target angle with the rotation in the reverse direction. Thereby, the riding on the side roller 6 of the pusher rod 2 can be prevented. Thereby, it becomes possible to narrow the space | interval of the side roller 6, and the lateral shift of the pusher rod 2 can further be suppressed. In addition to this, the diameter of the side roller 6 can be reduced, and the side roller 6 can be downsized.

  Moreover, in the said embodiment, although the conveyance direction T was changed 180 degree | times in the folding | turning part R, the angle to change may be 90 degree | times, for example. Further, there may be a plurality of folded portions R. The pusher unit according to the present invention is preferably applied to a continuous heat treatment furnace having a folded portion.

  The present invention can be applied to a continuous heat treatment furnace for performing a carburizing process on a workpiece.

DESCRIPTION OF SYMBOLS 1 Pusher unit 1a 1st pusher unit 1b 2nd pusher unit 2 Pusher rod 2a Claw 3 Drive mechanism 4 Rod cradle 4a 1st rod cradle 4b 2nd rod cradle 5 Support roller 6 Side roller 6a Side surface of side roller DESCRIPTION OF SYMBOLS 10 Continuous-type carburizing furnace 11 Partition door 12 1st temperature rising chamber 13 2nd temperature rising chamber 14 1st carburizing chamber 15 2nd carburizing chamber 16 3rd carburizing chamber 17 Diffusion chamber 18 Cooling chamber 19 Quenching chamber 20 Carry-in port 21 Lift lift 30 Control Device 40 Third pusher unit A _P pusher rod rotation axis A _R support roller rotation axis A _S side roller rotation axis R Folding part T Conveying direction W Workpiece

Claims (11)

A pusher unit used in a continuous heat treatment furnace for heat treating a workpiece,
It has a pusher rod with a circular longitudinal section,
A support roller having a rotation axis perpendicular to the rotation axis of the pusher rod in plan view;
A side roller having a rotation axis parallel to the rotation axis of the pusher rod,
The side roller is a continuous heat treatment furnace pusher unit provided so that the pusher rod can come into contact with the side roller during rotation. A plurality of the side rollers are provided,
2. The pusher unit for a continuous heat treatment furnace according to claim 1, wherein each side roller is arranged in a positional relationship such that a rotation axis of the pusher rod exists between rotation axes of the side rollers in a plan view.   The pusher unit for a continuous heat treatment furnace according to claim 2, wherein the side rollers are arranged so as to face each other in plan view. A plurality of pairs of opposing side rollers are provided,
The distance between the pair of opposed side rollers provided on the rear end side of the pusher rod is narrower than the distance between the pair of opposed side rollers provided on the front end side of the pusher rod. Pusher unit for continuous heat treatment furnace. A control device for controlling expansion and contraction operations and circumferential rotation operations of the pusher rod in the conveying direction;
The control device includes:
During the rotation of the pusher rod, after performing the first rotation control for rotating the pusher rod by the first angle in the first rotation direction, the second rotation direction opposite to the first rotation direction. Performing a second rotation control to rotate the second angle smaller than the first angle,
The continuous heat treatment according to any one of claims 1 to 4, wherein the first rotation control and the second rotation control are repeatedly performed to rotate the pusher rod to a target angle. Furnace pusher unit.   The pusher unit for a continuous heat treatment furnace according to any one of claims 1 to 5, wherein the rear end portion of the side roller is tapered.   The pusher unit for a continuous heat treatment furnace according to any one of claims 1 to 6, wherein a hard coating is applied to a surface of the support roller.   The pusher unit for a continuous heat treatment furnace according to any one of claims 1 to 7, wherein a hard coating is applied to a surface of the side roller.   A continuous heat treatment furnace for heat-treating a workpiece, comprising the pusher unit for a continuous heat treatment furnace according to any one of claims 1 to 8. It has a folded part where the conveyance direction of the workpiece changes,
The continuous heat treatment furnace according to claim 9, comprising: the first pusher unit that pulls and conveys the workpiece in the conveyance direction; and the second pusher unit that pushes and conveys the workpiece in the conveyance direction. A continuous heat treatment method for heat treating a workpiece,
Using the pusher unit for a continuous heat treatment furnace described in any one of claims 1 to 8,
When rotating the pusher rod provided in the pusher unit,
After performing a first rotation operation for rotating the pusher rod in a first rotation direction by a first angle, the second rotation direction opposite to the first rotation direction is greater than the first angle. Perform a second rotation to rotate a small second angle;
A continuous heat treatment method in which the pusher rod is rotated to a target angle by repeatedly performing the first rotation operation and the second rotation operation.

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