JP3028780U - Vertical hobbing machine - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] In a vertical hobbing machine, vibration, thermal displacement, and the like during cutting are reduced, and a machining dimension error of gear cutting is minimized to improve machining accuracy. SOLUTION: In a vertical hobbing machine, both a main column 2 and a sub column 3 are fixedly erected on a bed 1, and an over arm 8 is always provided between both upper parts of the main column 2 and the sub column 3. It is fixedly installed, and a closed loop structure is formed by bed 1, main column 2, over arm 8, and sub column 3. In addition to that, a hob support base 9 having a hob head 12 with a spindle head 11 for supporting the hob 7 on the front surface is slid in a hob cutting direction (X direction) in a hob saddle 17 holding the hob support base 9. The hob saddle 17 is movably provided, and is vertically movable within the main column 2.

Description

[Detailed description of the device]

[0001]

[Technical field to which the device belongs]

 The present invention is characterized in that, in a hobbing machine used for gear cutting of various gears, vibration, thermal displacement, etc. during cutting are reduced to improve gear cutting accuracy.

[0002]

[Prior art]

 The hobbing machine is generally classified into a vertical hobbing machine and a horizontal hobbing machine. The present invention relates to a vertical hobbing machine having a vertical axis for mounting a work (gear material). This vertical hobbing machine has a main column on one side of the bed, a sub column standing on the other side of the bed, and a table on the bed below the sub column. The work held by the support arm of the sub-column and the work arbor of the table is gear-cut by the hob provided on the main column side.

This vertical hobbing machine moves either the work or the hob structurally in order to bring the work on the table / sub-column side and the hob on the main column side closer to the required cutting position. There is a need. Tables and sub-columns are fixed, the main column moves on the bed, and the main column is fixed. Tables and sub-columns (specifically, a sliding table on which a rotary table and a sub-column are mounted). There is a table-moving type that moves the table [for example, Shinya Suzuki, "Engineering Machines and Tools (Practical Mechanical Engineering Bunko 13)", published by Rigaku Kogaku, 1974, 17th edition, pages 143 and below, by Yoshiaki Yamada. "Machining method (gear, gear cutting)", published by Power Co., Ltd., 1978, pp. 63 et seq., And Fig. 9 and Fig. 10 in the present application. Same as what I did].

In addition, in the above-mentioned table moving type, in order to fix the table / sub-column after the movement at that position, an over arm protruding laterally from the upper part of the main column to the sub-column side is provided at the upper part of the sub-column. There is also a structure that is clamped by hydraulic pressure [eg, design and production of gears and its durability, edited by Akira Wakuri, published by Yokendo Co., Ltd., 1982, pp. 53-54, and 11 and 12, the reference numerals in the drawings are the same as those given to the present invention].

[0005]

[Problems to be solved by the device]

 By the way, in the above-mentioned conventional general vertical hobbing machine, the load accompanying the cutting force of the gear cutting acts on the bed as a bending force through the main column and the sub-column. In addition, especially when machining a helical gear, the cutting force acts as a twisting force on the bed through the main column and sub-column. As a result, the bed is bent or twisted, which causes vibrations and machining size errors.

Further, since the hobbing of the hobbing machine is an intermittent cutting by the hob, the load applied to the bed fluctuates through the main column and the subcolumn. Therefore, the machining point between the hob and the workpiece also vibrates at a constant frequency, causing an error in machining dimensions.

Further, since the cutting fluid used during gear cutting is applied to the upper surface of the bed, a temperature difference is generated between the upper part and the lower part of the bed, and the central part of the bed is deformed upward due to thermal displacement (Fig. 10). As a result, the main columns and sub-columns standing upright on both sides of the bed will incline outward (see Fig. 10 above), and the relative positions of the hob and workpiece will change over time. This causes an error in the processing dimensions.

Moreover, since the hobbing machine vibrates a lot as described above, there is a problem that it is difficult to perform a gear cutting process using a cemented carbide hob which is hard but brittle.

On the other hand, in the hobbing machine having a table moving type and provided with an over arm, the table / sub column is moved to a predetermined position every time when gear cutting is performed, and the sub column is temporarily clamped by the over arm from the main column. (See FIG. 11). Therefore, the conventional hobbing machine with over-arm has the effect of slightly suppressing the vibration during gear cutting, but it is insufficient.

That is, in the conventional overarm in the hobbing machine with the overarm, it is necessary to clamp the sub-column before the gear cutting process, and after the gear cutting process, the clamp is released to retract the table / sub-colum. Since this overarm needs to be repeatedly clamped and released, it cannot be made highly rigid so that it has appropriate structural flexibility, and the clamping mechanism is also easy to repeat. There is a hydraulic clamp at one location.

Therefore, the fixing of the overarm by the clamp is effective against the force in the cutting direction of the hob (X direction = longitudinal direction of the overarm) because it is effective in the pulling direction, but at a right angle. The bending force in the Y direction (= short direction of the overarm) is insufficient because of the rigidity of the overarm. Also, it cannot be said that a single hydraulic clamp is enough to secure the sufficient overarm and subcolumn. After all, the bed is bent and twisted via the main column and sub-column, which causes vibrations and machining dimension errors.

Further, in the hobbing machine, as described above, the cutting fluid used during gear cutting is applied to the upper surface of the bed, and the bed is deformed due to thermal displacement due to the temperature difference between the upper part and the lower part of the bed. Removes the clamp at the end of processing to separate the main column overarm from the subcolumn. Therefore, the thermal displacement cannot be confined in the bed, main column, and sub-column, and the deformation of the bed causes the main column and sub-column to tilt and clamp them in the open state (see Figure 12 above). ). Therefore, the positional relationship between the hob and the work also has an error, which causes an error in the machining dimension.

Moreover, since the conventional hobbing machine with an overarm has the effect of slightly suppressing the vibration during gear cutting as described above, it is not sufficient, so the gear cutting by the hobbing machine is as described above. During intermittent cutting, the machining points of the hob and gear material vibrate during gear cutting, which also deteriorates machining accuracy, and it is difficult to machine using a carbide hob.

The present invention is intended to solve the problems of the conventional vertical hobbing machine. In other words, the purpose of the present invention is to bend or twist the bed through the main column or the sub-column during gear cutting, to deform the bed due to thermal displacement of cutting fluid, or to cut the bed by inevitable intermittent cutting on the hobbing machine. A vertical hob that minimizes vibrations during gear cutting by a hobbing machine by minimizing load fluctuations, greatly improves machining accuracy, and enables machining with a super hard hob. It is to provide a board.

[0015]

[Means for Solving the Problems]

 A The first aspect of the present invention is that the main column 2 is erected on one side of the bed 1 and the sub column 3 is erected on the other side of the bed 1, and the table 4 is provided on the bed 1 near the sub column 3. And a vertical hobbing machine in which the work 6 held between the support arms 5 of the sub-column 3 is subjected to gear cutting with a hob 7 provided on the main column 2 side. In addition to being fixedly installed on the bed 1, the overarm 8 is always horizontally installed between the upper portions of the main column 2 and the subcolumn 3 to fix the bed 1, the main column 2, the overarm 8 and the subcolumn 3 to each other. To form a closed loop structure.

B In the second aspect of the present invention, the main column 2 is erected on one side of the bed 1 and the sub column 3 is erected on the other side of the bed 1, and the sub column 3 is provided on the bed 1 near the sub column 3. In a vertical hobbing machine in which a work 6 held between a table 4 and a support arm 5 of a sub column 3 is subjected to gear cutting by a hob 7 provided on the main column 2 side, the main column 2 and the sub column 3 Are fixedly mounted on the bed 1, and the overarm 8 is always horizontally installed between the upper portions of the main column 2 and the subcolumn 3 so that the bed 1, the main column 2, the overarm 8 In the hob saddle 17 that holds the hob support base 9, a hob support base 9 having a closed loop structure formed by the sub-column 3 and having a hob head 12 with a spindle head 11 that pivotally supports the hob 7 is provided on the front surface. Together with the cutting direction (X-direction) F slidably provided hob, in which the Hobusadoru 17 in the main column 2 is provided to be movable in the vertical direction.

In the above structure, rotation of the hob 7, sliding of the hob support base 9 in the cutting direction, vertical feed movement, and other movements necessary for the hobbing machine are performed by the motors used as the respective drive devices. Is preferably automated by NC control.

[0018]

[Mode for Carrying Out the Invention]

 In the vertical hobbing machine according to the present invention, the main column 2 is erected on one side of the bed 1 and the sub columns 3 are erected on the other side thereof. Not only the main column 2 but also the sub column 3 is fixedly mounted on the bed 1. Unlike the conventional column moving type, neither column 2 nor 3 moves on the bed 1.

A table 4 is provided on the bed 1 near the sub-column 3, but this is also fixed to the bed 1 and moves on the bed 1 unlike the conventional table moving type. do not do.

An over arm 8 is provided so as to straddle between the upper portions of the main column 2 and the sub column 3. Unlike the conventional overarm, the overarm 8 is not clamped to the subcolumn only during gear cutting, but is always provided horizontally between the upper portions of the main column 2 and the subcolumn 3 in a fixed manner. With this, the bed 1, the main column 2, the overarm 8, and the subcolumn 3 form a normally closed loop structure.

Instead of fixing the columns 2 and 3 and the table 4 as described above, a hob support base body 9 is provided in the side portion of the main column 2 so that the hob can move in the cutting direction (X direction). is there. The front part of the hob support base 9 projects from the side of the main column 2, and a hob head 12 having a spindle head 11 pivotally supporting the hob 7 is attached thereto. The clamp 18 can be fixed at a position where the hob support base 9 slides a certain amount in the cutting direction (X direction) of the hob.

In order to move the hob supporting base 9 in the vertical direction, the hob saddle 17 holding the hob supporting base 9 can be moved in the vertical direction in the main column 1 by, for example, the feed screw 20. Good.

When gear cutting is carried out in the vertical hobbing machine according to the present invention having the above-described structure, first, the work (gear material) 6 is held by the table 4 and the subcob, as in the conventional vertical hobbing machine. The work is held by the work arbor 14 between the ram 3 and the support arm 5, and the work 6 is made rotatable by the table 4.

Next, the movement of the hob 7 in the cutting direction by gear cutting differs from that of the conventional vertical hobbing machine, and the hob support base 9 provided in the main column 2 is rotated by an NC motor. The inside of the hob saddle 17 may be slid by (not shown) and the feed screw 19. After moving to the fixed position, fix it with the clamp 18. For the vertical feed movement of the rotating hob 7, the hob support base 9 is moved vertically by another motor (not shown) that rotates under NC control and the feed screw 20. With this, the work 6 on which the hob is rotating is machined. The hob head 12 or the spindle head 11 can be turned with respect to the center line of the hob support base 9 so that the hob axis can be tilted.

As described above, in the vertical hobbing machine according to the present invention, both the main column 2 and the sub column 3 are fixedly mounted on the bed 1, and between the upper parts of the main column 2 and the sub column 3, The over arm 8 is always fixed and provided, and the bed 1, the main column 2, the over arm 8 and the sub column 3 are always integrated into a closed loop structure.

Therefore, in the conventional hobbing machine, the load caused by the cutting force of the gear cutting process acts as bending or twisting force on the bed through the main column having the hob and the sub-column supporting the work. Differently, it is received by the whole closed loop structure including the constantly fixed over arm 8, bed 1, main column 2 and sub column 3. Therefore, the load caused by the cutting force of the gear cutting process greatly suppresses the force acting on the bed 1 as bending or twisting, and the vibration and the machining dimensional error due to the gear cutting process are minimized.

Further, the gear cutting process of the hobbing machine is intermittent cutting, and in the conventional hobbing machine, the load applied to the bed via the main column and the sub column fluctuates, and the machining point between the hob and the work also vibrates. In this case as well, since it is received by the whole closed loop structure by the overarm 8 which is always fixed, the fluctuation of the load applied to the bed 1 and the vibration of the machining point between the hob 7 and the work 6 are minimized.

Further, the cutting liquid is applied to the upper surface of the bed 1 during gear cutting, and thermal displacement occurs due to the temperature difference between the upper and lower portions of the bed 1. However, even if the conventional hobbing machine has an over arm, it will be over-cut at the end of processing. Since the arms are unclamped and the main column / overarm and the subcolumn are separated, thermal displacement cannot be trapped inside the bed / main column / subcolumn, and the deformation of the bed causes the main column and subcolumn to tilt (Fig. 12). reference).

However, in the hobbing machine having the above-mentioned structure, the thermal displacement caused by the cutting fluid is confined in the always closed loop structure composed of the constantly fixed overarm 8, the main column 2, the bed 1 and the sub column 3. Therefore, the deformation of the bed 1 can be suppressed to a minimum, and the main column 2 and the sub column 3 can be prevented from tilting outward (see FIG. 4), and the relative position of the hob 7 and the work 6 changes. In this respect also, the dimensional error in processing is minimized.

Moreover, in the hobbing machine having the above-described structure, the overarm 8 is always fixed as described above, and unlike the conventional overarm, it is not necessary to repeatedly clamp and release the overarm, and thus the overarm 8 itself has high rigidity. It can be made of any material and is firmly fixed integrally to the main column 2 and the sub column 3. Therefore, not only against the force in the cutting direction (X direction) of the hob, but also against the force in the Y direction at a right angle thereto, the main arm 2 and the sub column 3 by the over arm 8 and the bed 1. It is possible to prevent the displacement by firmly holding and, and from this point as well, the main column 2 and the sub column 3 are prevented from tilting and the bed 1 is prevented from being bent or twisted, thereby improving the machining accuracy.

As described above, the hobbing machine of the present invention suppresses vibrations and the like to the minimum, so that it is possible to perform gear cutting using a super hard hob which has been difficult to use in the past.

[0032]

【Example】

 1 to 4 show an embodiment of a vertical hobbing machine according to the present invention, in which a main column 2 is erected on one side of a bed 1 similar to a conventional vertical hobbing machine. . A sub column 3 is erected on the other side of the bed 1 so as to face the main column 2. The main column 2 and the sub column 3 are both fixedly mounted on the bed 1, and unlike the conventional column moving type, do not move on the bed 1 in the cutting direction (X direction) of the hob.

A table 4 is provided on the bed 1 near the sub column 3, but this is also fixed to the bed 1 and the sub column 3 and is different from the conventional table moving type. , Do not move on the bed 1 in the cutting direction (X direction) of the hob. In order to hold the work (gear material) 6, similarly to the conventional vertical hobbing machine, the support arm 5 is provided on the side of the sub-column 3 and the work bar 14 is erected on the table 4 correspondingly. It is set up.

Then, an over arm 8 is provided laterally so as to connect between the upper parts of the main column 2 and the sub column 3 which are erected and fixed on the bed 1. Unlike the conventional hobing machine with an overarm, the overarm 8 is always fixed between the upper parts of the main column 2 and the subcolumn 3 and has sufficient rigidity. Here, a large number of tightening bolts are used. It is firmly fixed using 15. With this, the bed 1, the main column 2, the over arm 8 and the sub column 3 are always integrated into a normally closed loop structure.

On the other hand, in order to move the hob 7 in the cutting direction (X direction) as the work 6 instead of fixing the main column 2, the sub column 3 and the table 4 on the bed 1 as described above, The structure is different from the conventional hobbing machine.

That is, here, the hob support base 9 having a cylindrical shape is engaged and held in the lateral hob saddle 17 in the side portion of the main column 1, and the gear 16 is driven by an NC controlled motor (not shown). The hob support base 9 is slidable in the hob saddle 17 in the cutting direction of the hob by a lateral feed screw 19 which rotates. A hob head 12 with a spindle head 11 for supporting the hob 7 is provided at the front of the hob support base 9.

The hob support base 9 is provided with a clamp 18 so as to be fixed at a predetermined position after being moved in the cutting direction of the hob. In the clamp 18 here, an inner ring 21 having a split groove and a taper on the outer circumference is fitted on the outer circumference of the hob support base 9, and an outer ring 22 having a taper on the inner circumference is attached to the inner ring 21. The outer ring 22 is engaged with the outer ring 22, and the inner ring 21 can hold and clamp the outer periphery of the hob support base 9 by the wedge action of both tapers by pressing the outer ring 22 with hydraulic pressure. Needless to say, the clamp 18 is not limited to this.

Further, in order to feed and move the hob support base 9 in the vertical direction, here, a vertically oriented feed screw 20 rotated by a separately provided NC-controlled motor (not shown) and a ball screw (shown in the figure) screwed with the feed screw 20. The hob saddle 17 holding the hob support base 9 inside can be fed and moved in the vertical direction in the main column 1. The guided surface 13 formed on the front part of the hob saddle 17 is slidable along the vertical guide surface 10 on the front part of the main column 1.

The embodiment of the vertical hobbing machine according to the present invention is as described above, and has a normally fixed overarm and a normally closed loop structure. The following is a comparison between the hobbing machine and the hobbing machine regarding displacement and twist in the bed. This is compared with the calculation formula based on the assumption that the sub-column 3 and the over arm 4 are simple beams and have the same rigidity, and the supporting and fixing means are different. 5 to 8 showing the equation, the load is W, the displacement is δ, the load position is 1, the moment of inertia of area is I, and the longitudinal elastic modulus is E.

First, as shown in FIGS. 5 and 6, the displacement of the hob in the cutting direction (X direction) at the time of gear cutting is represented by the formula (1) for the conventional one and the formula (2) for the present embodiment. Therefore, when the displacement of the present embodiment of the normally closed loop structure is 1, the displacement of the conventional temporary clamp type is 1.75, which is the displacement of the present embodiment in the X direction. It is clear that the displacement is decreasing

Similarly, as shown in FIGS. 7 and 8, the displacement of the hob in the Y direction at right angles to the cutting direction is expressed by the formula (3) and by the formula (4) in the embodiment. As shown in the figure, when the displacement of the present embodiment having the normally closed loop structure is 1, the displacement of the conventional temporary clamp type is 4.57, and the displacement in the Y direction is reduced in the present embodiment. It is clear that they are doing so.

Further, the same applies to torsion, and when the displacement of the conventional temporary clamp type is 2, the displacement of the present embodiment having the normally closed loop structure is reduced to 1. As described above, in any of the cases, it is understood that the hobbing machine of the present embodiment has less displacement due to the load due to the cutting force during gear cutting, as compared with the conventional hobbing machine.

In the hobbing machine according to the present invention, the hob is moved in the cutting direction (X direction) by sliding the hob support base 9 provided in the main column 2. Therefore, if the hob supporting base 9 has a cylindrical shape as in the embodiment and is slidable in the hob saddle 17, the hob supporting base 9 is different from the conventional rail-shaped slide. It is easy to improve the processing accuracy for sliding in the cutting direction without blurring.

Further, in order to feed and move the hob support base 9 in the vertical direction, the guided surface 13 at the front of the hob saddle 17 moves along the vertical guide surface 10 at the front of the main column 1 as in the embodiment. If possible, the wide guide surface 10 can be accurately fed and moved in the vertical direction.

[0045]

[Effect of device]

 As is clear from the above, the vertical hobbing machine according to the present invention is subject to bending and twisting applied to the bed by the processing load associated with the cutting force during gear cutting, and the thermal displacement and deformation of the bed to which cutting fluid is applied. It is possible to minimize the tilt of the main column and sub-column, the fluctuation of the load applied to the bed due to the inevitable intermittent cutting by the hobbing machine, etc., and to greatly reduce the vibration during gear cutting by the hobbing machine. It is possible to significantly improve the processing accuracy while reducing the amount of time to a minimum, and it is possible to process using a super hard hob.

That is, even if the conventional vertical hobbing machine has an overarm, the bed is bent or twisted due to the processing load caused by the cutting force during the gear cutting process, and the vibration is increased or the machining size error occurs. Or the main column or sub-column tilts due to deformation of the bed due to thermal displacement of the cutting fluid, which changes the relative position between the hob and workpiece, which also increases the dimensional error of machining, and is inevitable on the hobbing machine. Due to the intermittent cutting, the load applied to the bed fluctuates, and the machining points between the hob and the workpiece also vibrate, causing a problem in machining accuracy.

On the other hand, in the vertical hobbing machine according to the present invention, the main column and the sub column are erected and fixed on the bed as described above, and the over arm is always fixed between the upper parts of both columns. The bed, main column, overarm, and subcolumn are always integrated to form a normally closed loop structure.

Therefore, unlike the conventional bob machine with an overarm, the load due to the cutting force of gear cutting is always received by the entire closed loop structure, so that the force acting as bending or twisting on the bed is greatly increased. It is possible to minimize vibration and machining size error due to gear cutting.

Further, the thermal displacement generated in the bed due to cutting fluid during gear cutting is always received by the entire closed loop structure and is confined inside. Therefore, the bed is deformed or the main column or sub column is tilted. Can be prevented, the relative position of the hob and the workpiece can be prevented from changing, and the machining dimension error can be minimized from this aspect as well.

Furthermore, since the hobbing gear cutting process is intermittent cutting, the fluctuation of the processing load applied to the bed, which is inevitable, is also received by the entire normally closed loop structure. Therefore, the vibration of the bed and the machining point between the hob and the workpiece Vibration can be suppressed to a minimum, the machining accuracy can be improved, and the gear cutting can be performed using the super hard hob.

Moreover, unlike the conventional table-moving type or column-moving type, the hob is moved in the cutting direction by sliding the cylindrical hob support base body provided horizontally in the main column. The cutting feed can be performed with high accuracy.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a vertical hobbing machine according to the present invention.

FIG. 2 is a partially cutaway front view of the vertical hobbing machine shown in FIG.

FIG. 3 is a schematic front view of an embodiment of a vertical hobbing machine according to the present invention.

FIG. 4 is a slightly exaggerated schematic front view showing the thermal displacement of the bed in the embodiment of the vertical hobbing machine according to the present invention.

FIG. 5 is a formula showing a displacement amount in the X direction in a conventional vertical hobbing machine with a temporary clamp type over arm.

FIG. 6 is an equation showing a displacement amount in the X direction in the vertical hobbing machine according to the present invention.

FIG. 7 is an equation showing a displacement amount in a Y direction in a conventional vertical hobbing machine with a temporary clamp type over arm.

FIG. 8 is an equation showing a displacement amount in a Y direction in a vertical hobbing machine according to the present invention.

FIG. 9 is a schematic front view showing a conventional table-moving vertical hobbing machine.

10 is a slightly exaggerated schematic front view showing thermal displacement of a bed in the vertical hobbing machine shown in FIG. 9. FIG.

FIG. 11 is a schematic front view of a conventional vertical hobbing machine with a temporary clamp type over arm.

FIG. 12 is a slightly exaggerated schematic front view showing the thermal displacement of the bed in the vertical hobbing machine shown in FIG. 11.

[Explanation of symbols]

 1-Bed 11-Spindle Head 2-Main Column 12-Hob Head 3-Sub Column 13-Guided Surface 4-Table 14-Work Arbor 5-Support Arm 15-Tightening Bolt 6-Work 16-Gear 7-Hob 17-Hob Saddle 8-over arm 18-clamp 9-hob support base 19-feed screw 10-vertical guide surface 20-feed screw 21-inner ring 22-outer ring

Claims (2)

[Scope of utility model registration request] 1. A main column 2 on one side of a bed 1
However, the sub-columns 3 are respectively erected on the other side, and the work 4 held between the table 4 provided on the bed 1 on the sub-column 3 side and the support arm 5 of the sub-column 3 is placed on the main column 2 side. In a vertical hobbing machine for gear cutting with a provided hob 7, both the main column 2 and the sub column 3 are fixed on the bed 1 and between the upper parts of the main column 2 and the sub column 3. A vertical hobbing machine in which the overarm 8 is always installed horizontally and the bed 1, main column 2, overarm 8 and subcolumn 3 form a closed loop structure. 2. A main column 2 on one side of the bed 1
However, the sub columns 3 are respectively erected on the other side, and the table 4 provided on the bed 1 near the sub columns 3 and the work 6 held between the support arms 5 of the sub columns 3 are placed on the main column 2 side. In a vertical hobbing machine for gear cutting with a provided hob 7, both the main column 2 and the sub column 3 are fixed on the bed 1 and between the upper parts of the main column 2 and the sub column 3. The overarm 8 is always installed horizontally, and a closed loop structure is formed by the bed 1, the main column 2, the overarm 8 and the subcolumn 3, and the hob head 12 with the spindle head 11 that supports the hob 7 is in the front. The hob support base 9 provided is slidably provided in the hob saddle 17 holding the hob support base 9 in the cutting direction of the hob.
A vertical hobbing machine in which the main column 2 is movable in the vertical direction.