JP5945952B2 - Shaving cutter - Google Patents

Description

  The present invention relates to a shaving cutter particularly used for a plunge cut shaving process among shaving processes used in a gear tooth surface finishing process.

In recent years, as the required accuracy of gears has improved, high-precision machining with a gear cutting tool has been required. This is the same in the shaving process that is the finishing process of the gear, and high tooth profile / tooth trace accuracy is required. In particular, the undulation of the tooth profile / tooth trace has been regarded as a problem.

  In particular, the plunge cut shaving process performed in the gear tooth surface finishing process is such that each time the work gear rotates once, the position of the serration cutting blade moves by the amount of deviation equal to the tooth trace direction, and each cutting blade acts. It is the process which cuts by. At this time, the amount of cutting with respect to the tooth surface of the cutting blade of the shaving cutter per one rotation of the gear is generally a very small amount of 1 μm or less.

  As such a shaving cutter, for example, Patent Document 1 discloses a shaving cutter in which one blade has different serration pitches on the forward rotation side and the reverse rotation side. By adopting such a shaving cutter configuration, the cutting amount of the left and right tooth surfaces of the work gear is made uniform, and the gear strength of the gear is improved.

  However, in the shaving cutter disclosed in Patent Document 1, when cutting the left and right tooth surfaces of the work gear, there is a possibility that the same tooth profile / tooth swell may occur on the left and right tooth surfaces. This is because there are two possible causes for the undulation of the tooth profile and tooth traces in the work gear, that is, due to the processing machine and due to the processing method.

  That is, the factor by the processing machine is that the shaving process is the rotation of the work gear and the shaving cutter (co-rotation), and the natural vibration of the work machine used during the shaving process is also propagated to the work gear. Conceivable. Further, the factor of the machining method is that the shaving process is a process in which a minute amount of cutting is repeated on the tooth surface of the gear to be cut, and the amount of processing per time by the cutting is generally as small as 1 μm or less. Therefore, every time the gear to be cut rotates, "cutting" and "uncutting (slip on the gear tooth surface without cutting)" occur. As a result, it is considered that the “cut part” and the “not cut part” appear as undulations of the tooth profile and tooth trace.

In view of this, Patent Document 2 discloses a shaving cutter that changes the amount of deviation with respect to the same tooth of the gear every time the machining gear is machined. This shaving cutter is characterized by improving the machining accuracy of the gear.

JP-A-63-57118 JP 2009-255276 A

By the way, the life of a general gear cutting tool is often judged by a decrease in the machining accuracy of the work gear. For example, if a predetermined number is machined from the start of gear machining, the gear cutting tool will be worn and the cutting ability will be reduced. Therefore, as the gear machining progresses, the machining accuracy of the work gear decreases, and it is finally determined that the gear machining is finished when the work accuracy of the work gear deviates from the target value. In other words, the actual number of machining from the machining start to the machining end is the (use) life of the gear cutting tool.

  In addition, the wear forms of the cutting blade of the shaving cutter include wear caused by cutting a gear to be cut of a high hardness material and rubbing (friction) wear resulting from the cutting sequence with respect to the cut gear. In particular, it is considered that this rubbing wear occurs due to the fact that the above-described gear machining by the shaving cutter is micro-cutting. In other words, when machining is performed so that the machining positions of the work gear continuously overlap, the processes of “cutting” and “non-cutting” are repeated for one tooth surface of the work gear. There are cases where gear processing proceeds. In this “non-cutting” process, the cutting blade of the shaving cutter is pressed against one tooth surface of the gear to be cut and rubbed. As a result, it is considered that the abrasion of the cutting blade of the shaving cutter occurs. .

Regarding the above-described shaving cutter of Patent Document 2, as shown in FIG. 7 of the same document, when the workpiece gear is machined, the amount of deviation is changed for each machining operation with respect to the same tooth of the gear. Yes. However, the machining positions of the work gears are machined so as to continuously overlap regardless of the amount of deviation. In addition, since the amount of cut per one time by the shaving cutter is also a typical minute amount of 1 μm or less, the process of “cutting” and “cutting without cutting” is performed on one tooth surface of the gear to be cut. Repeat the gear machining. Therefore, the shaving cutter shown in the document 2 has a problem that the wear of the cutting edge (of the shaving cutter) progresses and the tool life is shortened.

Accordingly, an object of the present invention is to provide a shaving cutter having a long tool life while maintaining a stable machining accuracy of a work gear.

In order to solve the above-described problems, in the present invention, a shaving cutter having a plurality of sets of a set of cutter teeth having the same serration pitch of the cutter teeth, the set of cutter teeth and A shaving cutter with different serration pitches of another set of cutter teeth group was used. By using this shaving cutter, the machining positions on the work gear by the cutting blade of the shaving cutter are dispersed (without overlapping). That is, when attention is paid to the same tooth surface of the work gear, the cutting of the shaving cutter and the tooth surface of the work gear are irregularly contacted to perform gear machining.

The second invention is a shaving cutter having an even number of cutter tooth groups. For example, in the case of a shaving cutter composed of cutter tooth groups having two types of serration pitches, the number of sets of cutter tooth groups having two types of serration pitches can be made even by setting a plurality of cutter tooth groups. can do.

As described above, by using the shaving cutter according to the present invention, the processing position of the cutting gear of the shaving cutter to the cutting gear is dispersed (without overlapping), so that the stable processing accuracy of the cutting gear is achieved. While maintaining the above, there is an effect that the tool life is extended.

It is a perspective view of the cutter tooth | gear 3 which comprises the shaving cutter 1 which shows an example of embodiment of this invention. FIG. 3 is a schematic partial development view of a shaving cutter 1 having cutter tooth groups 5 (5a, 5b) with different serration pitches 4 (4a, 4b) of the cutter teeth 3; It is a schematic side view of the shaving cutter 1 in the case of being composed of cutter tooth groups 5a and 5b having two different serration pitches 4a and 4b. It is a schematic diagram of the tooth surface of the work gear when the feed is given so as to cut 1 μm at a time with respect to the tooth surface of the work gear during cutting using the conventional shaving cutter and the product of the present invention.

An example of an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the shaving cutter 1 is constituted by a plurality of cutter teeth 3 each having a plurality of cutting blades 2. In particular, a plurality of cutter teeth 3 having the same serration pitch 4 of the cutting blade 2 are gathered to form a group of cutter teeth 5.

Further, as shown in FIG. 2, the shaving cutter 1 of the present invention has a cutter tooth group 5 (5a, 5b) configured by a plurality of cutter teeth 3 forming two different serration pitches 4a, 4b. The cutter tooth groups 5a and 5b are adjacent to each other.

For example, as shown in FIG. 3, when the shaving cutter 1 according to the present invention includes a cutter tooth group 5a having a serration pitch 4a and a cutter tooth group 5b having a serration pitch 4b, the cutter constituting the entire shaving cutter 1 The tooth group 5 is formed such that the cutter tooth group 5a and the cutter tooth group 5b are adjacent to each other.

  Next, the difference in the processing form at the time of cutting using the conventional shaving cutter and the shaving cutter according to the present invention will be described with reference to FIG. FIG. 4 is a schematic diagram of the tooth surface of the work gear when the conventional shaving cutter and the product of the present invention are used to feed the cutting surface so as to cut 1 μm at a time with respect to the tooth surface of the work gear. It is. It is assumed that the cutting process proceeds in the order of (I), (II), (III), (IV), and (V) shown in FIG. As shown on the left side of FIG. 4, for example, in the machining order (II) in the machining order (II), the machining form to the machining gear using the conventional shaving cutter is 1 μm deep from the tooth surface of the machining gear. It is further processed at a depth of 1 μm so as to partially overlap the processed part. That is, the cutting process using the conventional shaving cutter always proceeds in a manner that partially overlaps the previous processing position, and the processing amount (processing depth) is constant from the previous processing amount ( In the case of FIG. 4, 1 μm).

  On the other hand, the processing mode at the time of cutting using the shaving cutter according to the present invention does not overlap with the part processed in the processing order (I) in the processing order (II) as shown on the right side of FIG. Thus, it is newly machined with a depth of 2 μm from the tooth surface of the work gear. That is, in the cutting process using the shaving cutter of the present invention, the serration pitch differs for each cutter tooth group, so the cutting process does not necessarily proceed in a form that partially overlaps the previous machining position, and the work is irregularly cut. Cutting is performed on the gear.

A cutting test was performed using both the shaving cutter according to the present invention (hereinafter referred to as the present invention product) and the conventional shaving cutter (hereinafter referred to as the conventional product) as a comparative material, and The number of processing was compared. The specifications of the product of the present invention are a mixed form of module 2.45, helix angle 17 °, number of cutter teeth 89, serration pitch 2.0 mm and 2.1 mm. As a specific mixed form of different serration pitches, as shown in FIG. 3, a cutter tooth group having a serration pitch of 2.0 mm (corresponding to the cutter tooth group 5a in FIG. 3) and a cutter tooth group having a serration pitch of 2.1 mm ( 3) (corresponding to the cutter tooth group 5b in FIG. 3). On the other hand, the specifications of the conventional product are module 2.45, helix angle 17 °, number of cutter teeth 89, serration pitch 2.0 mm. The specifications of the work gear were a module 2.45, a pressure angle of 20 °, a helix angle of 32.2 °, and a number of teeth of 15.

In the cutting test, the present invention and the conventional product were shaved under test conditions of a cutter rotation speed of 170 rpm and a plunge feed speed of 0.7 mm / min. Here, the life of the shaving cutter (tool life) depends on whether or not the machining accuracy of the work gear deviates from the target value, or periodic variations of the tooth profile and tooth trace occur on the tooth surface of the work gear. Judgment based on whether or not.

As a result of the cutting test in the case of using the product of the present invention, the number that could be processed before reaching the tool life was 3572. On the other hand, as a result of the cutting test using the conventional product, the number that could be processed before reaching the tool life was 3100. Further, among the teeth composing the first-worked gear (first product), four equally divided teeth were selected, and the amount of waviness on the tooth surface was measured. As a result, the maximum waviness of the first product cut using the product of the present invention was 2 μm, whereas the maximum waviness of the first product cut using the conventional product was 1.5 μm. From this measurement result, the product of the present invention was able to obtain the effect of extending the (tool) life compared to the conventional product while keeping the stable machining accuracy of the (machined) gear to the same level as the conventional product.

DESCRIPTION OF SYMBOLS 1 Shaving cutter 2 Cutting blade 3 Cutter teeth 4, 4a, 4b Serration pitch 5 Cutter tooth group 5a One set of cutter tooth groups 5b Another set of cutter tooth groups

Claims (2)

A shaving cutter having a plurality of sets of a set of cutter teeth each having the same serration pitch of the cutter teeth,
A shaving cutter, wherein the set of cutter teeth and the other set of cutter teeth are different in serration pitch. The shaving cutter according to claim 1, wherein the cutter tooth group has an even number of sets.

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