JP2010280966A - Hardening tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hardening tool for small metal components having a long lifetime which is capable of entirely executing the uniform hardening of a large amount of small metal components represented by CVT (Continuously Variable Transmission) elements without causing any surface damage. <P>SOLUTION: The hardening tool for small metal components consists mainly of molybdenum. The hardening tool has a comb-teeth shaped part 3 consisting of a plurality of teeth parts 3T capable of continuously storing a large amount of small metal components 10 in a leaning manner in recesses between the teeth parts 3T. Each teeth part 3T is machined so as to be inclined at the predetermined angle α° with respect to the vertical direction. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a quenching jig used for quenching for the purpose of increasing the mechanical strength of small metal parts, and typically for quenching used when quenching a large amount of CVT (Continuously Variable Transmission) elements. It relates to a jig.

  FIG. 7 shows a general CVT element 10 ((a) is a front view, (b) is a side view) (hereinafter, this CVT element 10 is a representative example of small metal parts).

  The CVT element 10 illustrated in FIG. 7 (a) is in contact with the legs 12A and 12B, the leg central part 12C, the shoulders 13A and 13B, the recesses 14A and 14B, the head H, and the surface of the head H. It consists of the protrusion part 11 formed in convex shape. Thus, the CVT element 10 has a symmetrical structure when viewed from the front, and is balanced in weight on the left and right.

  On the other hand, the CVT element 10 shown in FIG. 7B, that is, the side view of FIG. 7A has a protrusion 11 on one side and a cavity 16 on the back side. Thus, the CVT element 10 has an asymmetric structure when viewed from the thickness direction, and has a center of gravity near the protrusion 11.

  The CVT element 10 is made of a metal having excellent heat resistance by punching or other metal processing. Two endless belts made of metal (not shown) pass through the recesses 14A and 14B of many CVT elements 10 to form a CVT belt (not shown).

  Since a constant load (force) is applied to the CVT belt at the time of automatic shift, a constant load (force) is also applied to the CVT element 10 of the component. Therefore, it is necessary to increase the mechanical strength of the CVT element 10.

  Therefore, conventionally, after CVT elements 10 after metal processing are randomly loaded into a basket (hereinafter referred to as “separate loading”), heat treatment is performed in a high-temperature non-oxidizing atmosphere for a certain period of time, and then oil at 160 to 180 ° C. The CVT element 10 is immersed in a bath and cooled, and quenching (in this specification, bath quenching by such a method is referred to as “bulk treatment”) has been performed.

  For example, regarding the above bulk treatment, Non-Patent Document 1 states that “bath quenching is a method in which a large amount of small parts are usually cooled in a bath coolant such as oil or water. Is uniformly cooled, and the development needs are always high. ”

JPO homepage (http://www.jpo.go.jp/shinryou/s_sonota/map/kagaku09/1/1-4-3.htm, “Metal heat treatment” P.2, third paragraph)

However, as can be seen from the latter stage of the above description of Non-Patent Document 1, there is a problem to be solved in bulk processing. The problem will be described below.
In the bulk processing, the CVT elements 10 are randomly stacked in the basket and quenched, so that the CVT elements 10 are overlapped and the overlapping portions are not sufficiently quenched. As a result, quenching unevenness is likely to occur in the CVT element 10, and quenching distortion (hereinafter simply referred to as “strain” as appropriate) occurs at a certain rate in the quenching lot. As a result, it is difficult to ensure the accuracy of the quenched CVT element 10, and further, there is a problem that a certain level of mechanical strength cannot be obtained satisfactorily.

  Therefore, as a countermeasure for such a defect, in bulk processing, the defect rate caused by quenching to the CVT element 10 is statistically grasped in advance, and the quenching is performed in consideration of the number of defects in advance, resulting in a CVT that has been quenched. A method with a low yield, such as removing and discarding the element 10 to secure the necessary production quantity, has been adopted.

  As described above, in the bulk processing, the quenching failure of the CVT element 10 is inevitably generated. Therefore, the quality inspection system for removing the defective product becomes excessive, and unnecessary inspection costs are incurred.

  In addition, because heat-resistant stainless steel metal is used as the component material for heat treatment jigs (baskets, nets, etc.) used in bulk processing, the frequency of jig change due to thermal deformation increases, and the jig It was short-lived and jig cost was high.

  In addition, in bulk processing, since a large amount of CVT elements 10 are put into the jig at a time, the CVT elements collide with each other before quenching and then overlap each other, so that surface scratches are inevitable.

  Therefore, when quenching a large amount of CVT elements, the present invention does not cause surface scratches on each CVT element, minimizes variations in the amount of distortion in the quenching lot, and can perform quenching treatment uniformly. The object is to provide a long quenching jig.

(Aspect of the Invention)
Hereinafter, embodiments of the invention will be shown and described. The items (1) to (4) correspond to the claims 1 to 4. The item (5) is an example relating to a method for quenching a small metal part in a mass production using the quenching jig according to the present invention.

(1) A quenching jig for small metal parts, which mainly includes molybdenum as a constituent material, and has comb teeth that can continuously stand a large amount of small metal parts.

Item (1) exemplifies a long-life (durable) quenching jig for small metal parts for quenching a large amount of small metal parts, typically CVT elements.
The constituent material of the quenching jig of item (1) is mainly composed of molybdenum (for example, molybdenum steel is used) because molybdenum is expensive (however, molybdenum is cheaper than tungsten). However, the coefficient of linear expansion is smaller than that of a conventional inexpensive stainless steel material (for example, SUS304 material).
. For this reason, thermal deformation due to the quenching temperature (for example, a high temperature of 850 ° C. to 900 ° C.) hardly occurs. In this respect, it can be used repeatedly, resulting in cost advantages. Incidentally, a stainless steel product is thermally deformed by a single quenching, and it is not possible to reduce the variation in the amount of distortion, which will be described later, and it is not suitable as a constituent material for a quenching jig in a mass production factory.

  With respect to the constituent material (the whole is 100 parts by weight), it is preferable to contain 98 parts by weight or more of molybdenum. This is because if it is less than 98 parts by weight, the heat resistance is deteriorated and the jig life is shortened.

(2) The small metal component can be placed in a recess formed between adjacent tooth portions of the comb tooth portion that is erected at a predetermined interval and holds the small metal component, and the comb Each tooth part of a tooth part is inclined at an angle of 1.5 ° to 8 ° with respect to the vertical direction.

  According to the quenching jig of this section, it is possible to quench a large amount of the CVT element, which is a small metal part to be quenched, with a defect rate of almost zero. This is because a large amount of CVT elements are aligned with a certain interval on the quenching jig, so that heating during quenching and cooling at the final stage of quenching are uniform, and in addition, a large amount of CVT elements are set in the quenching jig. This is because there is no generation of surface flaws because the layers do not overlap with each other during quenching.

By the way, if the CVT elements are manually placed one by one in the recesses formed between the adjacent tooth portions of the comb tooth portion, it is disadvantageous in terms of work cost.
However, if the automatic insertion machine already proposed by the applicant of the present application is used to place the CVT element on the quenching jig, the problem of work cost is solved. In particular, since a concave portion formed between adjacent tooth portions of the comb tooth portion exists at a certain distance and the quenching jig is long, the metal accessory component is accurately positioned by an automatic insertion machine. The CVT element can be naturally dropped from a vertically upper portion between the teeth of the comb teeth at a constant short distance, and can be inserted and placed.

  Furthermore, the quenching jig of this section is characterized in that “each tooth portion of the comb tooth portion is inclined at an angle of 1.5 ° to 8 ° with respect to the longitudinal direction and the vertical direction”. . This is because the quenching jig of this section is typically produced suitably for quenching of the CVT element, and in view of the structural characteristics of the CVT element described above, for the following reason It was decided.

  As described above, the automatic insertion machine inserts and places the CVT element by naturally dropping a certain distance in the vertical direction (for example, a distance of about 3 cm from the top of the comb portion) between the tooth portions formed on the comb portion. At this time, however, the CVT element has a center of gravity on the protruding portion side as described above, and is slightly inclined toward the protruding portion side. In consideration of this falling inclination, the inclination angle of each tooth portion was set, and the opening for inserting the CVT element into the concave portion between adjacent tooth portions was widened. Thereby, it becomes easy to insert and place the CVT element in the concave portion between the respective tooth portions.

  In addition, a large amount of CVT elements are inserted and placed in the quenching jig 1 and heated at a constant temperature in an airtight heat treatment furnace, which will be described later. An inert gas (nitrogen gas, argon gas, etc.) is blown uniformly over the element to cool the gas, and quenching is completed. At this time, if the CVT element is placed on the quenching jig in the vertical direction (inclination angle is substantially 0 °), scratching occurs when the CVT element is set on the jig. In the case of automation when setting the CVT element to the jig, there is a problem that the automatic insertion machine stops due to an automatic setting defect (see FIG. 5) for setting the CVT element to the jig. In this respect, it is meaningful to set the inclination angle α ° to a certain value or more.

On the other hand, when the CVT element is tilted excessively on the protrusion side in the quenching jig (when the tilt angle α ° is increased), the downward surface of the CVT element is cooled during the gas cooling with the inert gas. Quenching is incomplete because of the slow cooling rate.
In addition, in such a case, when the CVT element is naturally dropped, inserted, and placed between the comb teeth of the quenching jig from above by the automatic insertion machine, the adjacent CVT elements are prevented from colliding with each other. Therefore, the thickness of each tooth (Δt portion in FIG. 2) must be increased. This reduces the number of CVT elements placed on the quenching jig and reduces productivity.

As described above, the inventor of the present application has determined that the teeth of the comb teeth are inclined at an angle of 1.5 ° to 8 ° with respect to the longitudinal direction and the vertical direction as a result of intensive studies. (Further grounds for the angle range are described in the Examples section).
The angle slightly varies depending on parameters such as the shape, size, weight, position of the center of gravity, drop distance from the automatic insertion machine, and the like of the small metal parts. Therefore, the angle range is not strictly limited to 1.5 ° to 8 °, and can be appropriately changed by those skilled in the art.

(3) Each said tooth | gear part of the said comb-tooth part is arrange | positioned at equal intervals along the elongate direction of the said hardening jig | tool, (1) or (2) term | claim characterized by the above-mentioned. Hardening jig.

  This term illustrates the optimal formation state of each tooth portion of the comb tooth portion in the item (1) or (2). Small metal parts (CVT elements) can be aligned by arranging the teeth of the comb teeth at equal intervals along the longitudinal direction of the quenching jig. As a result, temperature unevenness during heating and cooling during quenching can be reduced. Further, the automatic insertion machine facilitates automatic insertion of small metal parts (CVT elements).

(4) The quenching jig according to any one of (1) to (3), wherein the metal accessory product is a CVT element used in a belt type continuously variable transmission.

In this section, the metal accessory product described in any one of the sections (1) to (3) exemplifies a CVT element used in a belt type continuously variable transmission (CVT) as a representative example.
However, the hardening jig according to the present invention is not limited to the CVT element hardening. For example, quenching of other small metal parts that have a symmetric structure when viewed from the front, such as a CVT element, but an asymmetric structure when viewed from the thickness direction, and require mechanical strength to be increased by quenching. It is also applicable to.

(5) In the airtight space, the step of automatically inserting and placing the CVT element into the recess formed between the teeth of the quenching jig described in (4), from substantially vertically above, The CVT element is heat-treated at any temperature of 850 ° C. to 900 ° C. for 10 to 30 minutes, and an inert gas is blown onto the CVT element from above substantially vertically, so that the heat-treated CVT element is And a step of cooling. A quenching method for a CVT element.

This section exemplifies a method of inserting and placing a CVT element in a quenching jig using an automatic insertion machine and then quenching the CVT element.
According to this section, the insertion and placement position of the CVT element to the quenching jig is determined by the automatic insertion machine, aligned along the comb tooth position of the quenching jig, and dropped from the automatic insertion machine. The CVT element to be placed can be placed at an appropriate position and angle of the quenching jig.
Thereafter, heat is applied to the CVT element for a certain period of time, and finally, the CVT element is gas-cooled with an inert gas such as nitrogen gas or argon gas to perform quenching. In this way, variation in the distortion amount of the CVT element can be kept low and the mechanical strength can be increased.

  The “airtight space” is preferably a heat treatment furnace that includes a chamber capable of sealing a gas from an external atmosphere, and includes a heater so that heat for quenching can be applied to the CVT element. The heat treatment furnace controls the heater to set the rate of temperature rise, the time for maintaining the temperature, etc., and the inert gas from above the hermetic space toward the CVT element vertically downward. It is preferable to provide a gas flow means capable of blowing.

  According to the present invention, small metal parts typified by CVT elements can be hardened with a long life, capable of uniform and quenching with a large amount and evenness, and suppressing variation in distortion amount without causing surface scratches. A jig can be provided.

It is the side view which observed the jig | tool for hardening which concerns on this invention from the side surface direction with respect to the elongate direction. FIG. 5 is an enlarged side view illustrating a state in which three CVT elements are inserted and placed in a quenching jig according to the present invention. In an Example and a comparative example, it is a graph which shows the temperature pattern at the time of mounting and quenching a CVT element in the jig | tool 1 for hardening. Regarding the variation in the amount of distortion generated in the CVT element, the CVT element is compared between the conventional quenching (comparative example) and the quenching by placing it on the quenching jig according to the present invention (example). It is a bar graph for doing. It is a graph which shows the experiment example performed in order to obtain the suitable range of each tooth inclination (alpha) degree of the jig | tool for hardening. (A) illustrates the normal state of the surface of the metal constituting the CVT element that has been suitably quenched, and (b) illustrates the abnormal state of the surface of the metal that constitutes the CVT element to which quenching has been performed inappropriately. It is a metal cross-sectional photograph to do. It is the front view (a) and side view (b) of the CVT element integrated in the CVT belt for motor vehicles.

Hereinafter, an embodiment according to the present invention (hereinafter referred to as “this embodiment”) will be described with reference to the accompanying drawings.
FIG. 1 shows a quenching jig 1 according to this embodiment. The overall configuration of the quenching jig 1 will be described with reference to FIG.
The quenching jig 1 includes end members (fixing members) 2A and 2B at both ends, and comb teeth having long and straight continuous teeth 3T between the end members 2A and 2B. The structure of the section 3 (having a constant width section in the depth direction of FIG. 1) is provided. The quenching jig 1 is placed in parallel with each other at regular intervals in the quenching jig 1 in a heat treatment furnace. By installing in this manner, small metal parts (typically, CVT elements 10) that are to be heat-treated are aligned in a certain direction, so that preparations for quenching in large quantities can be made.

  The teeth 3T of the comb teeth 3 are erected with a predetermined interval (preferably a constant interval). For this reason, a small metal part such as the CVT element 10 (hereinafter referred to as the CVT element 10 unless otherwise specified) is provided in the recess formed between the adjacent tooth portions 3T of the comb tooth portion 3. Is inserted and placed, and the CVT element 10 is leaned against each tooth 3T.

  The quenching jig 1 is mainly made of a material having heat resistance, a certain mechanical strength, and a long life (excellent durability) so that the quenching jig 1 itself is not deformed during quenching. It is preferable that it is easy to process. Therefore, it is preferable that the quenching jig 1 is made of a metal plate mainly containing molybdenum and is press-molded so as to have a comb shape.

  Next, with respect to the quenching jig 1, “each tooth portion of the comb tooth portion is inclined at an angle of 1.5 ° to 8 ° with respect to the longitudinal direction and a perpendicular direction”. Will be described below with reference to FIG.

  FIG. 2 shows a state in which the CVT element 10 is inserted and placed on the comb teeth 3 of the quenching jig 1 shown in FIG. 1 (only three are shown for convenience). As shown in FIG. 2, all the tooth portions 3T of the comb teeth 3 have a certain angle with respect to the vertical direction (the angle formed with the vertical direction is expressed as α ° as shown in FIG. 2), preferably 1.5. It is tilted at an angle of 8 ° to 8 °.

  In order to quench the CVT element 10 in a large amount, the CVT element 10 is inserted into the quenching jig 1 by free-falling the CVT element 10 from a short distance above the quenching jig 1 by an automatic insertion machine. It is preferable to automatically set one by one in the recesses between the tooth portions 3T one by one in the direction from the members 2A to 2B.

  At this time, since the center of gravity of the CVT element 10 is located closer to the protrusion 11, the CVT element 10 is slightly inclined toward the protrusion 11 during the free fall from the automatic insertion machine. Therefore, if the teeth 3T of the comb teeth 3 of the quenching jig 1 are tilted to some extent in advance so that the angles of the teeth 3T of the comb teeth 3 follow the inclination at the time of mounting from the time of dropping, the CVT is obtained. The element 10 is smoothly inserted and placed from above between the tooth portions 3T. Also, immediately after the insertion / placement, the CVT element 10 is balanced with the drag, gravity, and the gravity from each tooth portion 3T of the comb tooth portion 3 (further gas pressure and balance during gas cooling described later). It is placed in a stable state so as to lean against each tooth 3T. According to this stable mounting state, suitable quenching is possible. In particular, in the gas cooling stage, the cooling gas (for example, nitrogen gas) for cooling the CVT element 10 is maintained in such a stable mounting state even while the CVT element 10 is sprayed from above with a constant gas pressure. Therefore, the CVT element 10 is cooled in a stable state, and a metal structure (for example, martensite metal structure) having suitable mechanical strength not only inside but also the surface can be created (see FIG. 6).

  Furthermore, since the production cost is advantageous in mass production, it is preferable that as many CVT elements 10 as possible be mounted on one quenching jig 1. Therefore, it is better that the teeth 3T are close to each other. However, as can be seen from FIG. 2, when the tooth portions 3T are excessively close to each other, the CVT element 10 is already placed between the tooth portions 3T when the CVT element 10 is inserted and placed between the tooth portions 3T by natural fall from above. The probability that the CVT element 10 that has been inserted and the CVT element 10 that is to be inserted / placed will collide will increase. In particular, in order to continuously insert and place the CVT element 10 so that the protrusion 11 of the head H of the CVT element 10 does not contact or collide with the already mounted CVT element 10, It is necessary to suitably design the inclination and the thickness Δt of the tooth portion 3T as appropriate (see an experimental example described later).

  In addition, a constant gap (gap) is provided between the CVT element 10 and the recess between the tooth portions 3T so that the CVT element 10 can be smoothly inserted (or detached) without rubbing against the quenching jig 1. It is preferable to provide it. However, it is preferable that the gap is not too large so that the CVT element 10 does not have excessive loose fitting portions in the recesses between the tooth portions 3T. This is because the stable mounting state of the CVT element 10 in the quenching jig 1 is impaired.

[Examples and comparative examples]
In the following examples and comparative examples, the variation in distortion amount is shown by comparing the case where the CVT element 10 is automatically set on a quenching jig and quenched, and the case where the CVT element 10 is bulk processed.
<Preparation of small metal parts>
As representative examples of small metal parts, 3000 CVT elements 10 that were not heat-treated were prepared in each of the examples and comparative examples. The CVT element 10 was prepared as a metal stamped product having the following composition (weight%) (C: 0.70-0.76, Si: 0.15-0.35, Mn: 0.6-0.9, Cr: 0.45-0.55). Al: 0.02-0.06, P: 0.02max, S: 0.05max, balance Fe).

<Preparation of quenching jig>
A quenching processing jig 1 was prepared in which the inclination angle α ° of the tooth portion 3T of each comb tooth portion 3 was set to 6 °. Further, the quenching jig 1 has 125 CVT elements 10 in the form shown in FIG. 2, and leg portions 12A and 12B straddle the tooth portions 3T of the quenching jig 1 so that the leg portions 12A. The flat central portion 12C between 12B extends between the tooth portions 3T (the width portion in the depth direction of the paper surface of FIG. 2), and the flat central portion 12C between the leg portions 12A and 12B is between the tooth portions 3T. The dimensions were such that they could come into contact with the center of the recess and be placed in a stable state (Example). On the other hand, the same number of CVT elements 10 and stainless steel baskets as in the example were prepared for bulk processing (comparative example).

<Setting of CVT element>
In the case of the embodiment using the quenching jig 1, the end member 2 </ b> A shown in FIG. 1 is used by using an automatic insertion machine (not shown) suitably designed and manufactured in advance for the quenching jig 1. Along the direction 2 to 2B, the prepared number of CVT elements 10 were automatically inserted and placed so as to spontaneously fall in order from vertically above toward the adjacent tooth portions 3T. On the other hand, in the comparative example by the conventional bulk processing, the prepared number of CVT elements 10 were stacked in the basket.

<Hardening>
The quenching jig with the CVT element 10 inserted and placed therein is an non-oxidizing atmosphere, and an electric heater is installed so that heat is uniformly transferred to the entire interior, and the internal temperature pattern is applied to the electric heater. It sealed in the heat processing furnace (airtight chamber) provided with the sequencer which can be set, controlling an electric power value. In the heat treatment furnace in this state, a sequencer program was set to control the heater according to the temperature pattern shown in FIG. 3, and the heat treatment furnace was operated. Thus, the temperature is increased to 860 ° C. at a constant temperature increase rate, maintained at this temperature of 860 ° C. for 30 minutes, and then the heating is stopped, and then nitrogen gas (atmospheric pressure of 9.5 Bar to 10 Bar) is used. The quenching process was performed by cooling the CVT element 10 (Example).

  On the other hand, for the bulk treatment (comparative example), a basket in which CVT elements were stacked in a conventional manner was immersed in 180 ° C. oil for 5 minutes and quenched (comparative example).

<Evaluation> FIG. 4 shows a case in which the CVT element 10 is automatically set and quenched by using an automatic insertion machine in the quenching jig 1 in which the angle α (FIG. 2) of the tooth portion 3T is set to a constant value ( Example: The left bar graph) and the case of quenching by bulk treatment (comparative example) were subjected to comparative evaluation of variation in distortion amount of the CVT element 10 before and after quenching.

The distortion amount was measured according to the flatness of the CVT element 10 as a whole (more on the site, the thickness of the central portion 15 just below the protrusion 11 of the CVT element 10 is measured and used as a parameter for the distortion amount. (See FIG. 7)).
And the flatness which concerns before and after hardening was measured, and the amount of distortion was calculated | required by the following formula | equation (n = 30).

  Distortion = Flatness before quenching-Flatness after quenching

  Then, the degree of variation with respect to the obtained distortion amount was quantified by obtaining a statistical standard deviation. Furthermore, assuming that the degree of variation in the amount of strain for the bulk processing was 100, the relative value (converted value) of the amount of variation in the amount of strain in the processing using the quenching jig was obtained, and the bar graph shown in FIG. 4 was created.

  According to FIG. 4, when the quenching jig according to the example was used, the variation in distortion amount was reduced (improved) by half or less as compared with the bulk processing according to the comparative example. Thus, by performing quenching using the quenching jig according to Example 1, the same quenching could be performed more uniformly in the same lot (same quenching conditions) than in the conventional (bulk processing).

  In addition, the quenching jigs used in the examples did not deform at all after the quenching was completed, but the baskets used in the comparative examples were distorted to the extent that they could be seen with the naked eye.

[Experimental example]
Furthermore, an experimental example performed to obtain a preferable range of the inclination α ° of each tooth of the quenching jig will be described.
In this experimental example, the inclination angle α ° of the tooth 3T is set to 0 °, 0.5 °, 1.0 °, 1.2 °, 1.6 °, 2.3 °, 5.9 °, 6.4 °, 6.8 °, 7.4 °, 8.0 °, 8.4 °. , 8.8 °, 9.2 °, 9.6 °, 10.0 °, 10.5 ° using 17 quenching jigs set for each of the 17 points, each of n = 30 This was carried out for each CVT element 10.

  As shown in FIG. 5, when the inclination angle α ° is 0 °, 0.5 °, 1.0 °, 1.2 °, 1.6 ° (more than 5 points), the CVT element 10 is automatically set on the quenching jig 1. A failure that occurred (a failure caused by a collision during automatic setting) occurred.

On the other hand, as shown in FIG. 5, when the inclination angle α ° is 8.0 °, 8.4 °, 8.8 °, 9.2 °, 9.6 °, 10.0 °, 10.5 ° (seven points or more), the CVT element 10 (n = 30). Were automatically set on the quenching jig 1 and an abnormal layer (tallstite metal structure) was observed near the surface of the CVT element 10. On the other hand, a normal layer (martensitic metal structure) was observed at other inclination angles α °.
These observation results are considered from a cross-sectional photograph of an observation image of a layer including an abnormal layer near the surface in FIG. 6A and a normal layer in FIG. For the abnormal layer 2% or less shown in the lower right of the graph of FIG. 5, the area ratio of the abnormal layer to the normal layer in the cross-sectional layer was 2% or less using the cross-sectional photograph of FIG. means.

  According to this experimental example, the inclination α ° with respect to the vertical direction of the tooth portion 3T of the comb tooth portion 3 of the hardening jig 1 for quenching the CVT element 10 is preferably in the range of 1.5 ° to 8.0 °. there were.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

1: Quenching tool, 3: Comb teeth, 3T: Teeth, 10: Small metal parts (CVT element).

Claims (4)

  A quenching jig for small metal parts, which mainly includes molybdenum as a constituent material and has comb teeth that can continuously stand a large amount of small metal parts.   The metal accessory component can be placed in a recessed portion that is erected at a predetermined interval and formed between adjacent tooth portions of the comb tooth portion, and each tooth portion is perpendicular to the vertical direction. 2. The hardening jig for small metal parts according to claim 1, wherein the jig is inclined at an angle of 1.5 ° to 8 °.   3. The quenching jig according to claim 1, wherein the teeth of the comb teeth are arranged at equal intervals along a length direction of the quenching jig.   The quenching jig according to any one of claims 1 to 3, wherein the metal accessory product is a CVT element used in a belt-type continuously variable transmission.