JP2019000914A - Honing machine and processing method using the same - Google Patents

Abstract

To make it possible to improve a process tolerance without damaging a floating function of a jig even if the jig has one grind stone.SOLUTION: A honing tool 1 is provided with one honing grind stone 6 which can project and retract in a radial direction, and a work-piece holding jig 10 is provided with: a jig base 11; an outer rotary body 13 which is so supported as to be rotatable around a first horizontal axis 12 with respect to the jug base 11 and to be movable along the first horizontal axis 12; an inner rotary body 15 which is so supported as to be rotatable around a second horizontal axis 14, which extends in a direction perpendicular to the first horizontal axis 12 with respect to the outer rotary body 13 and to be movable along the second horizontal axis 14; and a work-piece holder 16 which is fixed to the inner rotary body 15, and which detachably positions and holds a work-piece 50. A jig weight 20 is suspended from the work-piece holder 16.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a honing machine that presses a honing grindstone against an inner diameter surface of a hole of a workpiece and polishes the inner diameter surface, and a processing method using the honing machine.

  2. Description of the Related Art Conventionally, a honing machine that grinds an inner diameter surface by pressing a grindstone attached to a cylindrical main shaft against a hole inner diameter surface of a workpiece, reciprocating and rotating while applying a certain load, is known. The honing machine performs machining by centering the tool and the workpiece on the tool side or the jig side and aligning them with the pre-machined holes. As what performs centering on the jig side, for example, one having a floating mechanism is known (see, for example, Patent Document 1).

  As a honing machine, for example, a small-diameter honing tool including a honing grindstone as in Patent Document 2 is known. The honing tool is reciprocated in the axial direction of the inner diameter surface of the hole to be machined with a small diameter (for example, within 20 mm) of the workpiece, and the honing tool is provided with a constant cutting amount while rotating around the axis. Honing is performed on the inner surface of the hole to be processed.

Japanese Patent No. 2609989 JP 2006-346837 A

  In the small-diameter honing tool as in Patent Document 2, since the grindstone extending mechanism is provided in the small-diameter shaft at the tip of the tool, only one honing grindstone is provided in a part in the circumferential direction. In the case of a single grindstone, load fluctuation due to stroke causes the tool or workpiece to tilt. Moreover, the load fluctuation | variation in rotation increases the motion to the circumference direction, and causes the motion which impairs a perfect circle shape. In addition, tilting occurs, and stable machining cannot be performed, and finishing accuracy cannot be improved.

  The present invention has been made in view of the above points, and an object of the present invention is to improve machining accuracy without impairing the floating function of a jig even in a honing tool having one grindstone. is there.

  In order to achieve the above object, in the present invention, a weight for reducing load fluctuation is provided on the lower side of a jig having a floating function.

  Specifically, in the first invention, a rotating main shaft that can reciprocate in the axial direction of the inner diameter surface of the hole to be machined in the workpiece and that can rotate about the axis, and a honing that is detachably attached to the tip of the rotating main shaft. A honing machine equipped with a tool and a workpiece holding jig that supports the workpiece in a floating state in a horizontal direction with the workpiece oriented so that the hole to be machined extends in the vertical direction is assumed.

And the said honing tool is equipped with one honing grindstone that can project and retreat in the radial direction,
The workpiece holding jig is
A jig base;
An outer rotating body supported so as to be rotatable about the first horizontal axis with respect to the jig base and movable along the first horizontal axis;
An inner rotating body supported so as to be rotatable about a second horizontal axis extending in a direction perpendicular to the first horizontal axis and movable along the second horizontal axis with respect to the outer rotating body;
A work holder fixed to the inner rotating body, removably positioning and holding the work;
A jig weight suspended from the work holder or the inner rotating body.

  According to the above configuration, since the jig weight is suspended from the work holder or the inner rotating body, the work of the jig can be easily centered by the action of the jig weight. In addition, since the jig weight is located below, a tensile force acts on the inner rotating body and the outer rotating body, and the static rigidity and dynamic rigidity are improved, and the damping performance is greatly improved.

In the second invention, in the first invention,
The jig weight is formed by overlapping a plurality of components.

  In other words, if an integral jig weight is used, the resonance point is lowered, and a structural band close to, for example, 6.6 Hz, which is a honing process condition, is obtained, and the vibration is operated with a simple movement. The amount will increase. However, according to the above configuration, since a plurality of components are configured to overlap each other, for example, since there is no fixed structure other than those fastening portions, the movement of shaking is complicated. By making it more complicated, the amount of operation can be further suppressed, and adverse effects due to the addition of jig weights can be prevented. As a result, the shaking is greatly reduced and the stability of the workpiece posture can be obtained. Due to this result and the floating mechanism of the workpiece holding jig, the force applied to the honing grindstone can be limited to the weight of the workpiece, and a constant pressure machining state can be realized only by the workpiece weight.

In the third invention, in the first or second invention,
The plurality of constituent elements are made of steel plates with black skin remaining on their overlapping surfaces.

  According to said structure, since the steel plates do not closely_contact | adhere on each other's overlapping surface, the effect which made the jig weight into the overlapping structure is more reliably exhibited.

In a fourth invention, in any one of the first to third inventions,
The weight of the jig weight can be changed to a weight that generates a jig-side moment that cancels the tool-side moment that presses the workpiece by the honing tool.

  According to said structure, if the honing resistance force is calculated | required from specific cutting resistance and the position where the force is added is specified, the jig | tool side moment which can negate the tool side moment is computable. A reaction force is set by appropriately providing a jig weight for generating the jig side moment below the work holder or the inner rotating body, and the force generated in the work holding jig is suppressed.

According to a fifth aspect of the present invention, there is provided a rotary main shaft that can reciprocate in the axial direction of the inner diameter surface of the hole to be machined in the workpiece and that can rotate about the axis, a honing tool that is detachably attached to the tip of the rotary main shaft, and the workpiece On the premise of a machining method using a honing machine equipped with a workpiece holding jig that supports the workpiece in a floating state in a horizontal state in a state where the hole to be machined extends in the vertical direction,
The above processing method is
The honing tool is provided with a single honing grindstone that can project and retract in the radial direction, and the work holding jig can be rotated about a first horizontal axis with respect to the jig base and the jig base. An outer rotating body supported to be movable along the first horizontal axis, and rotatable about a second horizontal axis extending in a direction perpendicular to the first horizontal axis with respect to the outer rotating body; A preparatory step of providing an inner rotating body supported movably along the second horizontal axis, and a work holder fixed to the inner rotating body and removably positioning and holding the workpiece;
A calculation process for calculating the weight of the jig weight that generates the jig side moment that cancels the tool side moment that presses the workpiece with the honing tool;
A workpiece attachment step of attaching the workpiece to the workpiece holder;
A weight suspending step of suspending a jig weight corresponding to the calculated weight to the work holder or the inner rotating body;
A grinding step in which the honing tool is reciprocated in the axial direction of the inner diameter surface of the hole to be machined while the honing tool is rotated around the rotation main shaft to press the honing grindstone against the inner diameter surface.

  According to the above configuration, since the jig weight is suspended from the work holder or the inner rotating body, the work of the jig can be easily centered by the action of the jig weight. In addition, since the jig weight is located below, a tensile force acts on the inner rotating body and the outer rotating body, and the static rigidity and dynamic rigidity are improved, and the damping performance is greatly improved.

  As described above, according to the present invention, the jig weight is suspended from the work holder or the inner rotating body of the work holding jig, so that the work can be easily centered by the action of the jig weight. Therefore, even with a single grindstone, the processing accuracy can be improved without impairing the floating function of the jig.

It is the II sectional view taken on the line of FIG. It is a perspective view which shows the state which is honing the workpiece | work with the honing tool which concerns on embodiment of this invention. It is the perspective view which looked at the state which is honing the workpiece | work with the honing tool which concerns on embodiment of this invention from another direction. It is a schematic sectional drawing which shows the relationship between a honing tool and each process surface when a honing tool moves to an upper end side. It is a schematic sectional drawing which shows the relationship between a honing tool and each process surface when a honing tool moves to a lower end side. It is a graph which shows the roundness in the 1st processing surface at the time of processing with the honing processing machine concerning the embodiment of the present invention. It is a graph which shows the roundness in the 2nd processing surface at the time of processing with the honing processing machine concerning the embodiment of the present invention. It is a graph which shows the roundness in the 3rd processing surface at the time of processing with the honing processing machine concerning the embodiment of the present invention. It is a graph which shows the roundness in the 4th processing surface at the time of processing with the honing processing machine concerning the embodiment of the present invention. The frequency response diagram at the time of hanging the jig | tool weight which concerns on embodiment of this invention is shown. It is a graph which shows the roundness in the 1st processing surface at the time of processing with the honing processing machine concerning a comparative example. It is a graph which shows the roundness in the 2nd processing surface at the time of processing with the honing processing machine concerning a comparative example. It is a graph which shows the roundness in the 3rd processing surface at the time of processing with the honing processing machine concerning a comparative example. It is a graph which shows the roundness in the 4th processing surface at the time of processing with the honing processing machine concerning a comparative example. The frequency response diagram at the time of hanging the jig | tool weight which concerns on a comparative example is shown.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 3 show a state in which a workpiece 50 is honed by the honing tool 1 of the honing machine according to the embodiment of the present invention. For example, the workpiece 50 is a valve block of a hydraulic device. Although not shown in detail, the honing machine itself may be of a known structure, for example, a rotatable main shaft 2 to which the honing tool 1 is attached and capable of rotating up and down, and rotating and rotating the main shaft 2 up and down. A driving means for reciprocating is provided. The rotational speed, the vertical reciprocating speed, the cutting amount, etc. of the rotary spindle 2 can be precisely controlled by a control device (not shown).

  As shown in FIG. 1, the honing tool 1 is configured to be inserted into a hole 51 to be machined in a workpiece 50 so as to be reciprocally movable in the axial direction and to be rotatable around the axial line. One possible honing grindstone 6 is provided. Specifically, the honing grindstone 6 is built in the tip 4 of the tool body 3 whose tip side is narrowed, and a grindstone pressing pin (not shown) inserted through the internal through-hole 5 is raised and lowered to an appropriate height. The amount of protrusion in the radial direction is adjusted by driving. For example, the tip 4 of the tool body 3 has a diameter within 20 mm and is considerably smaller than a normal one.

  The honing machine includes a workpiece holding jig 10 that supports the workpiece 50. The workpiece holding jig 10 is configured to be able to support the workpiece 50 so that the workpiece 50 is floated in the horizontal direction in a state where the workpiece hole 51 is oriented so as to extend in the vertical direction. The work holding jig 10 includes a jig base 11 formed of a plurality of metal members. As shown in FIG. 3, the jig base 11 includes, for example, a bottom plate 11b having a lower opening 11a and a pair of side plates 11c erected at opposing positions on the left and right sides of the bottom plate 11b. As shown in FIG. 1, a horizontal first horizontal shaft 12 is rotatably provided in the same straight line on the first bushes 12a provided at the opposing positions on the upper side of the pair of side plates 11c. An outer rotating body 13 is rotatably supported around the first horizontal shaft 12. Further, the shape of the outer rotating body 13 is not particularly limited, but first through holes 13a through which the first horizontal shaft 12 is inserted are respectively provided at opposing positions of the annular main body. The front end of the first horizontal shaft 12 is inserted into the first through-hole 13a with the first retaining pin 13c being retained, and the outer rotating body 13 is interposed between the pair of side plates 11c on the first horizontal shaft 12. It is supported with a gap. Thereby, for example, when the outer rotating body 13 moves together with the first horizontal shaft 12, it can move horizontally along the first horizontal shaft 12 by this gap, and can rotate around the first horizontal shaft 12. It has become.

  Further, second through holes 13b are respectively provided at positions shifted by 90 ° in the circumferential direction with respect to the first through holes 13a in the outer rotating body 13, and a second bush provided in the second through hole 13b. A second horizontal shaft 14 is inserted into 12b so as to be rotatable and horizontally movable. That is, the axial direction of the second horizontal axis 14 is perpendicular to the axial direction of the first horizontal axis 12 in plan view. The distal end side of the second horizontal shaft 14 is inserted into an inner through hole 15a provided at a position facing the cylindrical inner rotating body 15, for example, with the second retaining pin 15b being retained. As a result, the inner rotating body 15 is rotatable about the pair of second horizontal shafts 14, and the second horizontal is set by the gap between the outer peripheral surface of the inner rotating body 15 and the inner peripheral surface of the outer rotating body 13. It is supported so as to be horizontally movable along the shaft 14.

  The cylindrical main body of the inner rotating body 15 is provided with a work holder 16 that positions and holds the work 50 so as to be removable. Thus, the workpiece 50 is supported so as to be two-dimensionally movable horizontally and three-dimensionally swingable with respect to the jig base 11. The work holder 16 has a substantially cylindrical shape, is provided with a handle 16a at the upper end, and can be attached to and detached from the inner rotating body 15 with a mounting bolt 16b. By removing the mounting bolt 16b and pulling up the handle 16a, the entire work holder 16 can be detached from the inner rotating body 15. The lid member 16c may be removed and the workpiece 50 alone may be removed from the workpiece holder 16.

  A jig weight 20 is removably suspended from the lower portion of the work holder 16. Note that the jig weight 20 may be suspended from the lower surface of the inner rotating body 15, but it is preferable to suspend the jig weight 20 from the work holder 16 that can be easily attached and detached in consideration of a change in mass. The jig weight 20 is configured by superposing a plurality of components, for example, steel plates 21. This steel plate 21 is made of, for example, an annular steel plate with black skin remaining on the overlapping surfaces thereof, and may be made of other materials such as cast iron. For example, these steel plates 21 are fixed to the lower surface of the work holder 16 with weight mounting bolts 22 in a superposed state.

  As will be described later, the weight of the jig weight 20 can be appropriately changed so as to generate a jig-side moment M2 that cancels the tool-side moment M1 that presses the workpiece 50 by the honing tool 1. That is, the steel plate 21 having an appropriate weight may be appropriately overlapped so as to approach the calculated weight.

-Operation of honing machine-
Next, the operation of the honing machine according to this embodiment will be described.

  First, in the preparation step, the honing machine is prepared, and the honing tool 1 is attached to the tip of the rotary spindle 2. The honing tool 1 is provided with one honing grindstone 6 that can project and retract in the radial direction.

  Next, or in advance, in the calculation step, the weight 50 of the jig weight 20 that generates the jig side moment M2 that cancels the tool side moment M1 that presses the work 50 by the honing tool 1 is calculated (details will be described later).

  Next, the work 50 is attached to the work holder 16 in the work attachment process.

  Next, in the weight suspension step, a jig weight 20 corresponding to the calculated weight is prepared by stacking the steel plates 21, and it is suspended from the work holder 16.

  Next, the work holder 16 to which the jig weight 20 having an appropriate weight according to the work 50 is attached is fixed to the inner rotating body 15.

  Next, in the grinding process, while the honing tool 1 is rotated around the rotation spindle 2, the honing grindstone 6 is pressed against the inner diameter surface by reciprocating in the axial direction of the inner diameter surface of the work hole 51 of the workpiece 50. .

-Jig weight calculation procedure-
Next, an example of a procedure for calculating the weight of the jig weight 20 will be shown. First, the processing force F1 is obtained. The processing force F1 is calculated | required from chip thickness (cutting speed / rotation speed) x length x width x specific cutting resistance. For example, 0.03 / 210 × 27 × 2 × 0.24 = 0.00185 kgf (0.018 N). In other words, it is very small and can be ignored.

  Next, the pressing force F2 is obtained. The generated force is assumed using the measured value of the cutting shaft motor load during machining. For example, the measured value is 305N, and the component force of the 4 ° cone is Cos (4) × (305 / 9.8) = 31.046 kgf (304.25N). The whetstone engagement range is three locations of the first processed surface 50a to the third processed surface 50c, and is considered as 1/3 force per surface. The force applied to the first machining surface 50a is 31.046 / 3 = 10.34 kgf (101.33 N), and the force on each surface is + on the upper side and + on the lower side for convenience of analysis via the operating shaft. It describes as.

  As shown in FIG. 4A, when the grinding wheel stroke is at the upper part, the A surface is +10.3 kgf, the B surface is +10.34 kgf, the C surface is -10.34 kgf, and +10.34 kgf remains from the differential force. . As shown in FIG. 4B, when the grindstone stroke is at the lower part, the B surface is +10.34 kgf, the C surface is -10.34 kgf, the D surface is -10.34 kgf, and 10.34 kgf remains from the differential force. . That is, by moving the honing tool 1 up and down, positive and negative forces of 10.34 kgf are constantly generated.

  On the other hand, the operating resistance of the workpiece holding jig is 0.24 kgf (actually measured value), and when subtracted from the generated force, a positive / negative force of 10.1 kgf (98.98 N) is generated in the workpiece 50. This force has a cutting speed of φ0.001 mm / sec, and can be assumed by overlapping measured values at the time of speed change. In addition, since the normal honing process uses the processing method which controls the force of a cutting shaft, this force can be easily formulated originally.

  Next, the stroke force F3 generated by the stroke is obtained. When the calculation formula used in the calculation of the processing force F1 is used, 400/210 × 3.5 × 2 × 0.24 = 3.2 kgf (31.3 N). The length is set to 3.5 because the processing length is used. The above formula is the force when pulled straight, and the force is replaced as a component force (cross hatch angle) because there is a rotational direction.

  Assuming that machining conditions are φ11 (circumferential length 34.54 mm), 210 min−1, stroke F 400 mm / min, and 1.905 mm per rotation, the component force is Tan (1.905 / 34.54) = 3.157. Since it becomes °, the thrust direction is Cos (3.157) × 3.2 = 3.195 kgf (31.3 N). Since this force is received by the end of the wall, it is dispersed as it is in the 90 ° direction and a force is applied in the tool thrust direction. However, since the thrust direction rigidity is very strong, Consider that it can be treated as a pressing force. That is, a positive / negative force of 3.195 kgf (31.3 N) is generated in the workpiece 50.

  It should be noted that the component force in the rotational direction Sin (3.157) × 3.2 = 0.17 kgf is estimated to be absorbed more by the tool bending, and may be excluded from the influence.

  Accordingly, the force F4 for swinging the workpiece holding jig 10 is F4 = F1 + F2 + F3, and a fluctuation force of 0.00185 + 10.1 + 3.195≈13.296 kgf (130.3 N).

  Next, when considering the moment force using the lever principle, the tool side moment M1 is: honing resistance × distance at the load point + workpiece weight 1/2 (the portion above the operating axis) × work L1 / 2 midpoint distance = F (130.30 × L15.25 + (M91.532 / 2) × 16), and the jig side moment M2 is the additional weight × mounting distance + workpiece weight (below the operating shaft) × workpiece L1 / 2 Point distance = F29.4N to 39.2N × L (33) + (91.53 / 2) × 16 In the jig side moment M2 with a weight of 29.4N (3 kgf), the tool side moment M1 It was found that the jig side moment M2 having a weight of 39.2 N (4 kgf) exceeded the tool side moment M1 and was appropriate. It was found that the workpiece 50 can be prevented from shaking when the jig weight 20 of 2 N (4 kgf) is loaded.

-Comparative example-
Next, a comparative example in which the jig weight 20 of this embodiment is not used will be described. This comparative example differs from the present embodiment in that the jig weight 20 is not provided in the workpiece holding jig 10 of the above embodiment. When honing the first to fourth machining surfaces 50a to 50d shown in FIGS. 4A and 4B with the honing tool 1, if the jig weight 20 is not attached, as shown in FIGS. All of the three processed surfaces 50a to 50d have a low roundness and an irregular inner surface shape. This is because the workpiece holding jig is swaying due to load fluctuations during machining. Further, especially on the upper first machining surface 50a side, due to the weight of the work holding jig, the machining accuracy tends to deteriorate toward the upper part due to the addition of inertial force when returning. In this measurement, since the workpiece holding jig has a structure that is easy to move on the first horizontal axis 12, the cross-sectional shape is a spectacle shape on the first processing surface 50a and the second processing surface 50b. As described above, the workpiece holding jig may move in any direction due to the load fluctuation. Further, the inertial force is increased with respect to the movement of the work holding jig. Further, in the loading range of the workpiece 50, the weight of each portion of the workpiece holding jig is different, and the inertial force varies depending on the machining portion. Furthermore, depending on the structure of the workpiece holding jig, it has been found that there is a problem that there is a direction in which the workpiece can easily move in the planar direction.

  The role of the workpiece holding jig is to take an inclination originally, and then to keep the inclination stably. On the other hand, the workpiece 50 can be tilted by the tool guide pad when the tool is inserted. However, when the honing tool 1 is given a vertical stroke and rotation, the position of the load is different. The change causes the workpiece holding jig to shake. When this shake is about to return, a large impact force is generated, resulting in a large shake.

  FIG. 8 shows a frequency response diagram in a workpiece holding jig of a comparative example having no jig weight 20. In this comparative example, the resonance frequency was 0.25 Hz, and the characteristics were gradually attenuated to approximately 14 Hz. Since the damping property is gentle, the characteristic that it is easy to react to vibration up to 14 Hz was shown. That is, 14 Hz indicates the degree of inferiority in the rotation speed band used in the honing process. When a workpiece holding jig having a floating function was used, the working range was almost in a half range due to the swinging movement, which showed an unfavorable state.

-Example-
On the other hand, in the present embodiment, since the jig weight 20 is suspended from the work holder 16, centering is facilitated by the action of the jig weight 20. For this reason, as shown to FIG. 5A-FIG. 5D, it turned out that in any of the 1st-4th processed surfaces 50a-50d, it is improved so that it may approximate a perfect circle substantially.

  As can be seen from the frequency response diagram of the honing machine having the jig weight 20 of the present embodiment in FIG. 6, although there is no significant difference in dynamic stiffness from the comparative example, in the floating machining zone It can be seen that the attenuation is remarkably improved. It turns out that it is effective in suppression of the fluctuation | variation in a use band. As an effect of the jig weight 20, an effect of suppressing vibrations in a short time can be seen. For example, even if an integral jig weight having the same weight is suspended, the damping performance up to this point cannot be obtained. In order to obtain this characteristic, several steel plates 21 need to be stacked. In addition, the several steel plates 21 can be obtained more easily by bonding the unprocessed surface (black skin surface) than by the machined close bonding. In the present embodiment, since the number of the steel plates 21 to be loaded is small, the damping effect cannot be obtained. However, by increasing the number, the vibration is changed to a form to be converted into membrane vibration on the mating surface. Since many layers pass through this membrane vibration, it is considered that the characteristics exhibit excellent damping effect. Further, it is considered that the displacement is reduced by changing to the membrane vibration.

-Realization of constant pressure processing-
Next, realization of constant pressure machining will be described. As described above, the force F4 applied to the honing grindstone 6 by the processing is about 13 kgf (127 N). This force F4 can be suppressed by the weight of the jig weight 20. In a situation where the weight obtained with the same force is suspended, a situation where 13 kgf is always applied to the entire surface of the honing grindstone 6 is realized. This situation will continue unless the cutting conditions are changed. This situation is presumed to be in a constant pressure machining state.

  By providing the jig weight 20 below, it can be dispersed as the same force in the 360 ° circumferential direction. In addition, it is necessary to consider the position of the load point in terms of length by hanging the jig weight 20 downward, but in the honing grindstone 6 that hits in the longitudinal direction, the difference is about 10 mm, and there is almost no change. It is in. In addition, the processing conditions of the workpiece holding jig 10 are very low and a slow condition is applied, and the jig itself is insensitive (response frequency: 0.25 Hz). It can be said that the situation has become. Moreover, the pressure applied to the honing grindstone 6 can be increased by making the lower steel plate 21 heavier. This is connected to the pressure UP (efficiency UP) of constant pressure processing.

  In addition, when viewed from the front side, the honing grindstone 6 moves up and down in the stroke on the upper end side and the lower end side, so that the contact time is compared with the two second processing surfaces 50b and the third processing surface 50c. 1/2. For this reason, a reduction in the amount of removal occurs at a portion where the processing time is short. For this reason, the upper and lower central portions are cut more and the inner diameter becomes larger, which is caused by the difference due to the contact time of the honing grindstone 6. This correction can be easily improved by using a generally used method of increasing the cutting allowance.

-Effects of this embodiment-
As described above, in the present embodiment, since the jig weight 20 is located below, a tensile force acts on the inner rotating body 15 and the outer rotating body 13 to improve the static rigidity and dynamic rigidity, and the damping performance is greatly improved. To do.

  Since the jig weight 20 is suspended from the inner rotating body 15, the jig weight 20 can be easily centered. Further, since the jig weight 20 is at the lower side, a tensile force acts on the inner rotating body 15 and the outer rotating body 13 to improve the static rigidity and dynamic rigidity, and the damping performance is greatly improved.

  As described above, when the unitary jig weight 20 is used, the resonance point is lowered, and a structural band close to, for example, 6.6 Hz, which is a honing process condition, is obtained. This will increase the amount of movement. However, in this embodiment, since the some steel plate 21 is overlapped and comprised, since it does not have a fixed structure other than those fastening parts, for example, the motion of a shake becomes complicated. By making it more complicated, the operation amount can be further suppressed, and adverse effects due to the addition of the jig weight 20 can be prevented. Thereby, the shaking is greatly reduced, and the stability of the workpiece 50 posture is obtained. With this result and the floating mechanism of the workpiece holding jig 10, the force applied to the honing grindstone 6 can be limited to the weight of the workpiece 50, and a constant pressure machining state is realized only by the weight of the workpiece 50.

  In addition, since the plurality of steel plates 21 with the black skin remaining on the overlapping surfaces of each other are overlapped to form the jig weight 20, the jig weight 20 is not closely adhered to each other, and the jig weight 20 has an overlapping structure. Is demonstrated more reliably.

  Further, for example, when the honing resistance force is obtained from the specific cutting resistance and the position where the force is applied is specified, the jig weight 20 that generates the jig side moment M2 that can cancel the tool side moment M1 is provided on the work holder 16. The reaction force is set by appropriately providing the lower portion, and the force generated in the workpiece holding jig 10 is pressed down.

  Therefore, according to the honing machine according to the present embodiment, even the honing tool 1 having one honing grindstone 6 can improve machining accuracy without impairing the floating function of the workpiece holding jig 10.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use.

1 Honing tool
2 Spindle
3 Tool body
4 Tip
5 Through hole
6 Honing wheel
10 Work holding jig
11 Jig base
11a downward opening
11b Bottom plate
11c side plate
12 First horizontal axis
12a 1st bush
12b 2nd bush
13 Outer rotating body
13a First through hole
13b Second through hole
13c First retaining pin
14 Second horizontal axis
15 Inside rotating body
15a Inside through hole
15b Second retaining pin
16 Work holder
16a handle
16b Mounting bolt
16c Lid member
20 Jig weight
21 Steel plate (component)
22 Weight mounting bolt
50 workpieces
50a-50d 1st-4th processed surface
51 Hole to be machined

Claims (5)

A rotating main shaft that can reciprocate in the axial direction of the inner diameter surface of the hole to be machined in the workpiece and that can rotate about the axis, a honing tool that is detachably attached to the tip of the rotating main shaft, and the workpiece has the hole to be machined. In a honing machine equipped with a workpiece holding jig that supports the workpiece in a floating state in the horizontal direction in a state of being oriented to extend in the vertical direction,
The honing tool includes one honing grindstone that can project and retract in the radial direction,
The workpiece holding jig is
A jig base;
An outer rotating body supported so as to be rotatable about the first horizontal axis with respect to the jig base and movable along the first horizontal axis;
An inner rotating body supported so as to be rotatable about a second horizontal axis extending in a direction perpendicular to the first horizontal axis and movable along the second horizontal axis with respect to the outer rotating body;
A work holder fixed to the inner rotating body, removably positioning and holding the work;
A honing machine comprising a jig weight suspended from the work holder or the inner rotating body. The honing machine according to claim 1,
A honing machine characterized in that the jig weight is formed by overlapping a plurality of components. The honing machine according to claim 2,
The honing machine characterized in that the plurality of constituent elements are made of steel plates with black skin remaining on their overlapping surfaces. In the honing machine according to any one of claims 1 to 3,
The honing machine characterized in that the weight of the jig weight can be changed to a weight that generates a moment that cancels out the moment of pressing the workpiece by the honing tool. A rotating main shaft that can reciprocate in the axial direction of the inner diameter surface of the hole to be machined in the workpiece and that can rotate about the axis, a honing tool that is detachably attached to the tip of the rotating main shaft, and the workpiece has the hole to be machined. In a machining method using a honing machine equipped with a workpiece holding jig that supports the workpiece in a floating state in a horizontal state in a state of being oriented to extend in the vertical direction,
The honing tool is provided with a single honing grindstone that can project and retract in the radial direction, and the work holding jig can be rotated about a first horizontal axis with respect to the jig base and the jig base. An outer rotating body supported to be movable along the first horizontal axis, and rotatable about a second horizontal axis extending in a direction perpendicular to the first horizontal axis with respect to the outer rotating body; A preparatory step of providing an inner rotating body supported movably along the second horizontal axis, and a work holder fixed to the inner rotating body and removably positioning and holding the workpiece;
A calculation process for calculating the weight of the jig weight that generates the jig side moment that cancels the tool side moment that presses the workpiece with the honing tool;
A workpiece attachment step of attaching the workpiece to the workpiece holder;
A weight suspending step of suspending a jig weight corresponding to the calculated weight to the work holder or the inner rotating body;
A grinding step of pressing the honing grindstone against the inner diameter surface by reciprocating in the axial direction of the inner diameter surface of the hole to be machined while rotating the honing tool around the rotation main shaft. Processing method using a honing machine.