Position correction member

Abstract

To improve a yield of a scissors gear.SOLUTION: A plurality of types of position correction members 1 are prepared in accordance with a position correction amount of correcting relative positional relation between main gear teeth 5 and sub gear teeth 6 in a scissors gear circumferential direction (rotating direction) in order to attach a scissors gear 2 to a mating gear. The position correction member 1 is mounted to an outer peripheral surface of the scissors gear 2, and corrects relative positional relation between a main gear 3 and a sub gear 4 so that the sub gear teeth are accommodated on the inner side of the main gear teeth 5, viewed in the scissors gear axial direction. Mountain parts 22 can continuously come into contact with the main gear teeth 5 and the sub gear teeth 6 in the axial direction of the scissors gear 2. A step 24 having a height in accordance with the corresponding position correction amount is formed on a side surface 23a on a side of receiving a load from the scissors gear out of side surfaces 23 opposed to tooth surfaces 8 of the scissors gear 2.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a position correction member that is attached to a scissors gear and corrects the positional relationship between the teeth of the main gear and the teeth of the sub-gear of the scissors gear so that they overlap in the circumferential direction of the scissors gear.

Background Art

[0002] For example, Patent Document 1 discloses a scissors gear having a first gear (main gear) that meshes with a mating gear, and a second gear (sub-gear) that meshes with the mating gear and is relatively rotatable in parallel in the axial direction with respect to the first gear, and suppresses the generation of tooth contact noise and meshing noise with the mating gear.

[0003] When assembling a scissors gear with a mating gear, it cannot be assembled to the mating gear without backlash.

[0004] Therefore, if a member (position correction member) that can correct the relative positional relationship between the teeth of the first gear and the teeth of the second gear so that they overlap in the circumferential direction (rotation direction) of the scissors gear can be prepared, it becomes possible to assemble the scissors gear to the mating gear.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, the first gear and the second gear each have dimensional tolerances in their respective teeth. The dimensional tolerances of the teeth of the first gear and the teeth of the second gear may deviate either to the side of reducing the tooth size or to the side of increasing the tooth size respectively. That is, even if the dimensions of each part of the scissors gear are within the dimensional tolerance, there is variation in the amount of position correction when correcting the relative positional relationship between the two so that the teeth of the first gear and the teeth of the second gear overlap in the circumferential direction (rotation direction) of the scissors gear.

[0007] Therefore, with the specifications of the prepared position correction members, even if the dimensions of each part of the scissors gear are within the dimensional tolerance, (in some cases, it may not be possible to attach it to the scissors gear,) the relative positional relationship between the two cannot be corrected so that the teeth of the first gear and the teeth of the second gear overlap in the circumferential direction (rotation direction) of the scissors gear, and there is a risk that the yield of the scissors gear will deteriorate.

[0008] That is, there is still room for further improvement in correcting the relative positional relationship between the two so that the teeth of the first gear and the teeth of the second gear of the scissors gear overlap in the circumferential direction (rotation direction) of the scissors gear.

Means for Solving the Problem

[0009] The position correction member of the present invention is attached to the scissors gear and corrects the relative positional relationship between the main gear teeth and the sub-gear teeth of the scissors gear so that they overlap in the circumferential direction of the scissors gear, and is characterized in that a plurality of types are prepared according to the amount of position correction when correcting the relative positional relationship between the main gear teeth and the sub-gear teeth.

Effect of the Invention

[0010] According to the present invention, by properly using a plurality of types of prepared position correction members, if the dimensions of each part of the main gear and the sub-gear are within the dimensional tolerance, it becomes possible to attach the position correction member to the scissors gear, and the relative positional relationship between the main gear teeth and the sub-gear teeth in the circumferential direction of the scissors gear can be corrected so that it can be assembled to the mating gear.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0013] The position correction member 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is an explanatory view schematically showing a state in which the position correction member 1 according to the first embodiment of the present invention is attached to the scissors gear 2. FIG. 2 is an explanatory view schematically showing an example of the scissors gear 2. FIG. 3 is an explanatory view schematically showing the positional relationship along the circumferential direction of the scissors gear between the main gear teeth 5 and the sub-gear teeth 6 of the scissors gear 2. (a) shows a case where the relative positional relationship between the main gear teeth 5 and the sub-gear teeth 6 is not corrected so that they overlap in the circumferential direction of the scissors gear (scissors gear rotation direction), and (b) shows a case where the relative positional relationship between the main gear teeth 5 and the sub-gear teeth 6 is corrected so that they overlap in the circumferential direction of the scissors gear (scissors gear rotation direction). FIG. 4 is a perspective view showing an example of the position correction member 1 according to the first embodiment of the present invention. FIG. 5 is an explanatory view schematically showing the state of the shipping inspection of the scissors gear 2.

[0014] As shown in FIG. 1, the position correction member 1 is attached to the scissors gear 2.

[0015] As shown in FIGS. 1 and 2, the scissors gear 2 has a main gear 3 that meshes with a mating gear (not shown), and a sub-gear 4 that meshes with the same mating gear (not shown) as the main gear 3 and has the same number of teeth and the same pitch as the main gear 3. The scissors gear 2 has the main gear 3 and the sub-gear 4 coaxially overlapped and arranged. The scissors gear 2 is assembled so that the main gear 3 and the sub-gear 4 are in a state of being applied with a force in the circumferential direction of the scissors gear (scissors gear rotation direction) by an elastic member (not shown) such as a spring. The scissors gear 2 eliminates backlash by sandwiching the teeth of the mating gear with the main gear teeth 5 formed on the outer periphery of the main gear 3 and the sub-gear teeth 6 formed on the outer periphery of the sub-gear 4. Note that the main gear 3 has the same tip circle diameter and root circle diameter as the sub-gear 4.

[0016] The scissors gear 2 is formed such that the main gear teeth 5 are larger than the sub-gear teeth 6 so that the sub-gear teeth 6 can fit (be hidden) behind the main gear teeth 5 when viewed in the axial direction of the scissors gear. Further, the tooth width of the main gear teeth 5 is formed to be larger than the tooth width of the sub-gear teeth 6.

[0017] The scissors gear 2 is attached to, for example, a crankshaft (not shown) or a balance shaft (not shown) of an internal combustion engine. The mating gear is attached to, for example, a balance shaft to which a balance weight (not shown) is attached when the scissors gear 2 is attached to the crankshaft. The mating gear is attached to the crankshaft when the scissors gear 2 is attached to the balance shaft, for example.

[0018] In the assembled state of the scissors gear 2, as shown in Fig. 3(a), the main gear teeth 5 and the sub-gear teeth 6 do not completely overlap in the circumferential direction (rotation direction) of the scissors gear, and a part of the sub-gear teeth 6 protrudes from the main gear teeth 5. Therefore, there is a possibility that the scissors gear 2 cannot be assembled to the mating gear by being caught by the teeth of the mating gear due to a part of the sub-gear 4 protruding from the main gear teeth 5.

[0019] Therefore, when assembling the scissors gear 2 to the mating gear, the amount of deviation between the main gear teeth 5 and the sub-gear teeth 6 along the circumferential direction (rotation direction) of the scissors gear is corrected using the position correction member 1 so that the scissors gear 2 can be assembled to the mating gear. Specifically, for example, as shown in Fig. 3(b), the amount of deviation of the sub-gear teeth 6 with respect to the main gear teeth 5 along the circumferential direction (rotation direction) of the scissors gear is corrected using the position correction member 1 so that the main gear teeth 5 and the sub-gear teeth 6 overlap in the circumferential direction (rotation direction) of the scissors gear.

[0020] The position correction member 1 is attached to the scissors gear 2 to correct the relative positional relationship in the circumferential direction (rotation direction) of the scissors gear 2 between the main gear teeth 5 and the sub-gear teeth 6 so that the scissors gear 2 can be assembled to the mating gear at the meshing position with the mating gear of the scissors gear 2. Specifically, the position correction member 1 corrects the relative positional relationship between the main gear 3 and the sub-gear 4 by a predetermined position correction amount in the direction in which the main gear teeth 5 and the sub-gear teeth 6 overlap in the circumferential direction (rotation direction) of the scissors gear. The position correction member 1 corrects the relative positional relationship between the two so that, for example, the entire sub-gear teeth 6 are hidden behind the main gear teeth 5.

[0021] The scissors gear 2 can be assembled to the mating gear by correcting the relative positional relationship between the main gear teeth 5 and the sub-gear teeth 6 so that they overlap in the circumferential direction (rotation direction) of the scissors gear.

[0022] On the other hand, even if the dimensions of each part of the scissors gear 2 are within the dimensional tolerance, there is variation in the correction amount (position correction amount) required when correcting the relative positional relationship between the main gear teeth 5 and the sub-gear teeth 6 in the circumferential direction (rotation direction) of the scissors gear so that it can be assembled to the mating gear. That is, the position correction amount can be a different value for each assembled scissors gear 2.

[0023] However, the range of variation of the position correction amount can be predicted using the dimensional tolerances of the main gear 3 and the sub-gear 4. That is, if the dimensions of each part of the scissors gear 2 are within the dimensional tolerance, it is possible to predict what range of values the position correction amount required when correcting the relative positional relationship between the main gear teeth 5 and the sub-gear teeth 6 in the circumferential direction (rotation direction) of the scissors gear when assembling the scissors gear 2 to the mating gear can take.

[0024] Therefore, variations in the relative positional relationship between the main gear teeth 5 and the sub-gear teeth 6 in the circumferential direction (rotation direction) of the scissors gear 2 due to dimensional tolerances of the scissors gear 2 are predicted, and a plurality of position correction members 1 with different position correction amounts are prepared so as to cope with this variation. That is, the position correction members 1 of the first embodiment are prepared in a plurality of types according to the position correction amount for correcting the relative positional relationship between the main gear teeth 5 and the sub-gear teeth 6 in the circumferential direction (rotation direction) of the scissors gear 2 so that the scissors gear 2 can be assembled to the mating gear. More specifically, the position correction members 1 of the first embodiment are prepared in three types corresponding to three cases: when the dimensional tolerance of each part of the scissors gear 2 is within the dimensional tolerance, when the position correction amount is maximum, when the position correction amount is minimum, and when the position correction amount is intermediate between the maximum and the minimum.

[0025] As shown in FIGS. 1 and 4, the position correction member 1 has an arc-shaped base portion 21 along the outer peripheral surface of the scissors gear 2 and a plurality of crest portions 22 having a wedge-shaped cross section that project from the base portion 21 and are inserted into the tooth grooves 7 of the scissors gear 2.

[0026] The position correction member 1 is attached to the outer peripheral surface of the scissors gear 2 and corrects the relative positional relationship in the circumferential direction (rotation direction) of the scissors gear 2 between the main gear teeth 5 and the sub-gear teeth 6 so that the scissors gear 2 can be assembled to the mating gear at least at the meshing position with the mating gear. More specifically, the position correction member 1 is, for example, a clip member capable of correcting (fixing) the relative positional relationship between the main gear 3 and the sub-gear 4 so that the sub-gear teeth 6 are accommodated inside the main gear teeth 5 when viewed in the axial direction of the scissors gear.

[0027] The crest portion 22 is capable of continuously contacting the main gear teeth 5 and the sub-gear teeth 6 along the axial direction of the scissors gear 2, and a step 24 having a height corresponding to the corresponding position correction amount is formed on the side surface 23a on the side that receives the load from the scissors gear 2 among the side surfaces 23 facing the tooth surface 8 of the scissors gear 2. Note that the step 24 may not be formed on the side surface 23b that does not receive the load from the scissors gear 2.

[0028] The crest portion 22 has a first portion 25 facing the main gear teeth 5 and a second portion 26 facing the sub-gear teeth 6.

[0029] The crest portion 22 is formed such that the thickness along the circumferential direction (rotation direction) of the scissors gear of the first portion 25 is thinner than the thickness along the circumferential direction (rotation direction) of the scissors gear of the second portion 26. The crest portion 22 is formed such that the thickness along the circumferential direction (rotation direction) of the scissors gear of the second portion 26 is formed to be a thickness corresponding to the corresponding position correction amount, and is formed to be thicker as the corresponding position correction amount is larger.

[0030] The step 24 has a step surface 27 parallel to a plane orthogonal to the scissors gear rotation axis formed at the boundary between the first portion 25 and the second portion 26. The step 24 becomes larger as the corresponding position correction amount is larger.

[0031] Accordingly, when correcting the amount of displacement along the circumferential direction (rotation direction) of the scissors gear of the sub-gear teeth 6 with respect to the main gear teeth 5, the position correction member 1 is configured to support the main gear teeth 5 on the surface by the first portion 25 and support the sub-gear teeth 6 on the surface by the second portion 26.

[0032] The assembled scissors gear 2 attaches the position correction member 1 and sets it, for example, in a shipping inspection jig 32 to which an inspection gear 31 corresponding to the mating gear is attached as shown in FIG. 5. The scissors gear 2 is shipped when it is confirmed in the shipping inspection jig 32 that it is assembled to the inspection gear 31.

[0033] Since a plurality of types of the position correction members 1 of the first embodiment described above are prepared according to the position correction amount, by properly using the plurality of types of the prepared position correction members 1, if the dimensions of each part of the main gear 3 and the sub-gear 4 are within the dimensional tolerance, it becomes possible to attach them to the scissors gear 2, and the relative positional relationship between the main gear teeth 5 and the sub-gear teeth 6 in the circumferential direction (rotation direction) of the scissors gear can be corrected so that they can be assembled to the mating gear.

[0034] That is, by preparing a plurality of types of position correction members 1, it becomes possible to correct the Cizers gear 2 so that it can be assembled to the mating gear for a plurality of different position correction amounts, and the yield of the Cizers gear 2 in the assembly process of the Cizers gear 2 can be improved.

[0035] Furthermore, by properly using a plurality of types of position correction members 1 according to the position correction amount, it is possible to improve the yield of the Cizers gear 2 at the time of shipment and prevent the acceptance of the Cizers gear 2 that cannot be attached to the mating gear that meshes with the Cizers gear 2.

[0036] Also, if the position correction member 1 is attached to the Cizers gear 2, the Cizers gear 2 can be attached to the mating gear that meshes with the Cizers gear 2. That is, if it is possible to attach the position correction member 1 to the Cizers gear 2, it can be determined in advance that the Cizers gear 2 can be attached to the mating gear that meshes with the Cizers gear 2.

[0037] Hereinafter, other embodiments of the present invention will be described. Note that the same components as those in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted.

[0038] A second embodiment of the present invention will be described with reference to FIGS. 6 and 7. The position correction member 41 of the second embodiment is not attached to the teeth of the Cizers gear 2, but is a cylindrical pin member inserted into a Cizers gear through hole 42 formed along the Cizers gear axis direction. The Cizers gear through hole 42 is composed of a first through hole 43 formed in the main gear 3 and a second through hole 44 formed in the sub gear 4.

[0039] In the second embodiment, when the relative positional relationship between the main gear teeth 5 and the sub gear teeth 6 of the Cizers gear 2 is a positional relationship that allows assembly to the mating gear, the first through hole 43 and the second through hole 44 overlap and are formed to be continuous along the Cizers gear axis direction.

[0040] Then, as shown in FIG. 6, the position correction member 41 of the second embodiment is attached to the scissors gear 2 so as to penetrate the first through hole 43 and the second through hole 44. FIG. 6 is an explanatory diagram schematically showing a state in which the position correction member 41 according to the second embodiment of the present invention is attached to the scissors gear 2.

[0041] The position correction member 41 of the second embodiment has a columnar shaft portion 45 inserted into the scissors gear through hole 42 and, for example, a flat columnar head portion 46 having a diameter larger than the inner diameter of the scissors gear through hole 42. The outer diameter of the shaft portion 45 is formed to be smaller than the inner diameter of the first through hole 43 and the inner diameter of the second through hole 44, which are the inner diameters of the scissors gear through hole 42.

[0042] A plurality of types of the position correction member 41 of the second embodiment are prepared according to the amount of position correction so that the scissors gear 2 can be assembled to the mating gear. More specifically, the position correction member 41 of the second embodiment is provided in three types corresponding to three cases: when the dimensional tolerance of each part of the scissors gear 2 is within the dimensional tolerance, when the position correction amount is maximum, when the position correction amount is minimum, and when the position correction amount is intermediate between the maximum and the minimum. The outer diameters of the shaft portions 45 are different from each other. For example, as shown in FIG. 7, the outer diameter of the shaft portion 45 is formed to be larger as the corresponding position correction amount is larger. FIG. 7 is an explanatory diagram schematically showing the size relationship between the shaft portion 45 of the position correction member 41 according to the second embodiment of the present invention and the scissors gear through hole 42. FIG. 7(a) shows the shaft portion 45 when the position correction amount is maximum, FIG. 7(b) shows the shaft portion 45 when the position correction amount is intermediate between the maximum and the minimum, and FIG. 7(c) shows the shaft portion 45 when the position correction amount is minimum.

[0043] Such a position correction member 41 of the second embodiment can exhibit substantially the same operational effects as the position correction member 1 of the first embodiment described above.

[0044] As described above, the specific embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit thereof.

[0045] For example, the position correction member 1 of the first embodiment may form a step with a ridge formed continuously across the first portion 25 and the second portion 26 on the side surface 23 of the peak portion 22, rather than at the boundary between the first portion 25 and the second portion 26. In this case, the peak portion 22 is formed such that the first portion 25 and the second portion 26 have the same thickness, and the ridge is formed such that the amount of protrusion from the side surface 23 in the second portion 26 is larger than that in the first portion 25. And in this case, when correcting the amount of displacement along the circumferential direction (rotation direction) of the scissors gear of the sub-gear teeth 6 with respect to the main-gear teeth 5, the main-gear teeth 5 are supported at the tip of the ridge formed in the first portion 25, and the sub-gear teeth 6 are supported at the tip of the ridge formed in the second portion 26.

Explanation of Reference Numerals

[0046] 1... Position correction member 2... Scissors gear 3... Main gear 4... Sub-gear 5... Main-gear teeth 6... Sub-gear teeth 7... Tooth groove 8... Tooth surface 21... Base portion 22... Peak portion 23... Side surface 23a... Side surface 23b... Side surface 24... Step 25... First portion 26... Second portion 27... Step surface 31... Inspection gear 32... Shipping inspection jig 41... Position correction member

Claims

1. A position correction member attached to a shears gear that sandwiches the teeth of a mating gear with main gear teeth formed on the outer circumference of a main gear and sub-gear teeth formed on the outer circumference of a sub-gear, characterized in that the relative positional relationship between the main gear teeth and the sub-gear teeth is corrected so that the main gear teeth and the sub-gear teeth overlap in the circumferential direction of the shears gear, and a plurality of types are prepared according to the position correction amount when correcting the relative positional relationship between the main gear teeth and the sub-gear teeth.

2. The position correction member has a crest portion that is inserted into the tooth groove of the shears gear, wherein the crest portion is characterized in that a step corresponding to the corresponding position correction amount is formed on a side surface facing the tooth surface of the shears gear. The position correction member according to claim 1.

3. The crest portion has a first portion facing the main gear teeth and a second portion facing the sub-gear teeth, the thickness along the circumferential direction of the shears gear of the first portion is formed to be thinner than the thickness along the circumferential direction of the shears gear of the second portion, the thickness along the circumferential direction of the shears gear of the second portion is formed to be a thickness corresponding to the corresponding position correction amount, the step is formed at the boundary between the first portion and the second portion. The position correction member according to claim 2.

4. The step is characterized in that it becomes larger as the corresponding position correction amount becomes larger. The position correction member according to claim 2.

5. The step is formed on the side that receives a load from the shears gear. The position correction member according to claim 2.

6. The plurality of types are three types: when the position correction amount is at its maximum value, when the position correction amount is at its minimum value, and when the position correction amount is at an intermediate value between the maximum and the minimum. The position correction member according to claim 1.

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