JPH0551425B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a precision finishing honing machine that grinds a workpiece with high precision.

<Prior Art> Conventionally, for example, a wrapping device for grinding the inner wall surface of a cylinder with high precision is disclosed in Japanese Patent Laid-Open No. 51-39498.

As shown in FIG. 5, this lapping device has a horn 2 having a grinding wheel 1 attached to its lower end and connected to a main shaft 3. An eccentric tire 6 is connected to both ends of a pin 4 extending through the main shaft 3 in a direction perpendicular to the axis of the main shaft 3 via a radial ball bearing 5.
is fitted (see Figure 6). Reference numeral 7 denotes an annular seat fixed to the spindle head 300 through which the spindle 3 is inserted, and the eccentric tire 6 can roll on its upper surface 7a as the spindle 3 rotates. Reference numeral 8 supports the main shaft 3 with a ball thrust bearing disposed in the lower part of the main shaft head 300. 9 is an upper lid screwed onto the upper end of the spindle head 300, and 18 is a lower lid fixed onto the lower end of the spindle head 300. 10 is a coiled compression spring fitted onto the main shaft 3, 11 is a spring holder for the coiled compression spring 10, 12 is a thrust ball bearing, and the elastic biasing force of the coiled compression spring 10 presses the eccentric tire 6 toward the upper surface 7a. ing. A pulley 13 has a spline (not shown) carved on the inner circumferential side that engages with a spline carved into the upper end of the main shaft 3, and is fitted into the main shaft 3 so as to be able to swing freely. Reference numeral 14 denotes a V-belt that is wound around a rotational drive source (motor) 15 and a pulley 13. 16 is a pinion that is pivotally supported on a support shaft (not shown) disposed on the side of the spindle head 300, and 17 is a manual handle that rotates the pinion 16.
300c is a rack carved in the axial direction on the outer peripheral surface of the spindle head 300, and meshes with the pinion 16. 1
9 is a table chuck disposed below the grinding wheel 1 to fix the workpiece W; 20 is the table chuck 1;
9 is a pulley fixed to a rotating shaft protruding downward from the center of the lower surface; 22 is a pulley 20 and a rotational drive source 2;
This is a V-belt wrapped around 1 (motor).

Therefore, after aligning the grindstone 1 and the workpiece W, the workpiece W is fixed to the table chuck 19. Then, the table chuck 19 is horizontally rotated by the rotary drive source 21, and at the same time, the main shaft 3 is horizontally rotated by the rotary drive source 15 in a direction opposite to the rotation direction of the table chuck 19.

In this way, the eccentric tire 6 pivotally attached to the main shaft 3 rotates while revolving on the upper surface 7a of the annular seat 7.
At this time, since the eccentric tire 6 is eccentric by an amount of eccentricity 6a, when the main shaft 3 rotates once, the main shaft 3 makes a small reciprocating motion up and down by an amount twice the amount of eccentricity 6a. In this state, use the manual handle 17 to
When the spindle 6 is rotated, the spindle head 300 descends downward, and the grindstone 1 cuts into the workpiece W to grind it to a predetermined accuracy.

In addition, Japanese Patent Publication No. 56-30149 discloses a device for making a rod-shaped grindstone attached to the end of the spindle move up and down in a large reciprocating manner along with the spindle head by a distance corresponding to the machining area of the workpiece. A honing device is disclosed that is configured to further provide a device for making a small reciprocating motion up and down, and to superimpose large and small up and down reciprocating motions on a bar-shaped grindstone.

<Problems to be Solved by the Invention> However, the conventional wrapping device as described above has the following problems. That is, (1) Since the main shaft 3 is supported on the main shaft head 300 by one ball thrust bearing 8, the useful life of the ball thrust bearing 8 is short due to center runout, and the rotation accuracy of the main shaft 3 is poor.

(2) Since the outer circumferential surface of the eccentric tire 6 fitted to the radial ball bearing 5 has the same diameter, the outer circumferential speed differs between the outer and inner surfaces during rotational movement, which causes slippage and heat generation, causing irregular wear. There was a problem that the small up and down reciprocating movements often became irregular.

(3) While the main shaft 3 rotates while making a small reciprocating motion up and down, the eccentric tire 6, which rotates while revolving around the upper surface 7a, has the full weight of the main shaft 3 and a coiled compression spring when the main shaft 3 descends to the bottom dead center. Since the elastic biasing force 10 acts, shocking vertical vibrations occur and the service life of the radial ball bearing 5 is shortened.

(4) The small up and down reciprocating movement of the main shaft 3 is caused by eccentric tires 6
Although it depends on the revolution and rotation of the spindle head 300
Since the large up-and-down reciprocating motion depends on the rotational operation of the manual handle 17 by the operator, accurate reciprocating motion operation is extremely difficult and the machining accuracy of the workpiece W becomes unstable.

(5) Since a mechanism for cutting into the workpiece W by the grindstone 1 is not incorporated, there is only a polishing function using a wrapping tool, and it is difficult to manage the machining accuracy of the workpiece W.

(6) A device that uses a small vertical reciprocating device to make a small reciprocating motion of the main shaft and a large reciprocating device that moves it up and down by a distance corresponding to the processing area of the workpiece, has an inertial force. becomes large, making it difficult to increase the speed of the small vertical reciprocating motion. Note that the bar-shaped grindstone has a problem in that the inner diameter of the workpiece changes as the grindstone wears.

<Means for Solving the Problems> This invention has been made to solve the above problems, and its purpose is to reduce the diameter of the machined hole in the workpiece from a large diameter to a small diameter, and to increase the length of the hole. By providing a precision finishing honing machine that can achieve higher machining accuracy than before, even for short to long holes, and even for bottomed holes, and allows easy selection of the material of the whetstone. be.

This invention has been made to achieve the above object, and includes a spindle head supported by a vertically extending column so as to be movable in the vertical direction, and a spindle head that shares an axis within the spindle head and is supported so as to be movable up and down. a transmission member, a main shaft rotatably provided on the transmission member, a horn having an appropriate number of grindstones disposed at the lower end of the main shaft and equipped with a grindstone diameter expansion mechanism, and a horn for driving the main shaft. a driving device for rotating the horn; an arm having a female ball screw threaded in the vertical direction and protruding from the side of the spindle head; and an arm provided parallel to the axis of the spindle; The ball screw is provided with a male ball screw screwed in a pair with a female ball screw, and a rotational drive source provided to be able to rotate the male ball screw in forward and reverse directions, and the spindle head is reciprocated in the axial direction of the spindle. a large up-and-down reciprocating device that moves a horn provided at the lower end of the spindle up and down by a distance commensurate with the processing area of the workpiece; a small vertical reciprocating device that has a crankshaft and causes the main shaft to undergo a small reciprocating movement up and down via the transmission member by the rotation of the crankshaft, with the upper limit of the amplitude being a distance commensurate with the machining area; The grindstone diameter expansion mechanism includes a grindstone diameter expansion rod having a tapered portion at a lower end and movable coaxially and axially within the main shaft, and a pair of input shafts. A differential gear mechanism includes a connected input gear and a planetary gear that meshes with the input gear, and an output gear that outputs the revolution of the planetary gear as rotation; and one input shaft of the differential gear mechanism. a gear mechanism that transmits the rotation of the main shaft; a reversible rotation drive source capable of rotating the other input shaft of the differential gear mechanism in forward and reverse directions; a second gear threadedly coupled to a threaded portion of the second gear; a second gear slidingly coupled to the second gear, driven by the movement of the second gear in the axial direction, and having one end thereof for transmitting the movement; a sliding metal fitting having a bolt, the bolt passing through a notch window provided in the main shaft so that the grindstone diameter expanding rod can be moved up and down; The precision finishing honing machine is characterized in that the grinding wheel diameter expanding rod is lowered by differential rotation with the rotation of the drive source to enlarge the machining diameters of the appropriate number of grinding wheels.

<Operation> The present invention is constructed as described above, and the main shaft is driven by a drive device to rotate a horn having an appropriate number of grindstones.

A large vertical reciprocating device reciprocates a rotating main shaft up and down a distance commensurate with the processing area of the workpiece.

Further, the small vertical reciprocating device transmits the small vertical reciprocating motion to the main shaft, which is reciprocating vertically by a distance commensurate with the processing area, via the transmission member.

The horn rotates by superimposing large and small reciprocating movements, and grinds the workpiece by enlarging the processing diameters of an appropriate number of grindstones.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

In Figs. 1 to 3, reference numeral 2 denotes a horn having an appropriate number of grindstones 1 radially attached to its lower end, and a main shaft 3 fixed vertically to its upper end.

Reference numeral 13 denotes a pulley, and a spline (not shown) is carved on the inner peripheral side to mesh with a spline 3a carved on the upper end of the main shaft 3. 15 is a rotational drive source (motor) for the main shaft 3, and a V-belt 14 is wound between the pulley 15a and the pulley 13.

The main shaft 3 is supported by radial bearings 80 and 81 fitted to the upper and lower ends of the transmission member 200. As a result, the transmission member 200 rotatably supports the main shaft 3 and is vertically and integrally connected to the main shaft 3. Further, the transmission member 200 is provided within the spindle head 300 so as to share an axis, and spring receivers 76 and 7 are fixed to the upper and lower ends of the spindle head 300, respectively.
It is elastically supported by coiled compression springs 78 and 79 supported by 7 so as to be movable up and down. 200
b is a protruding portion formed laterally at the intermediate portion of the transmission member 200, and is a protruding portion formed on the side of the intermediate portion of the transmission member 200, and
is fitted.

50 is a long male ball screw inserted into the column 302 parallel to the axis of the spindle 3;
It is screwed into a female ball screw (not shown) threaded into an arm 300a that protrudes laterally from the arm 300a.
Reference numeral 51 denotes a rotational drive source (reversible motor) fixed to the column 302 and connected to the ball male screw 50 by a shaft coupling 52 . Thrust ball bearings 54 and 55 are arranged at the upper and lower ends of the column 302, and support the male ball screw 50. When the male ball screw 50 is rotated by the rotary drive source 51, the spindle head 300 is guided by the column 302 and can make a large reciprocating motion up and down.

Reference numeral 300c is a penetrating portion that protrudes in a direction opposite to the direction in which the arm 300a protrudes, into which a radial ball bearing 84 is fitted. The axial center of the radial ball bearing 83 and the axial center of the radial ball bearing 84 are eccentric. 85 is a crankshaft supported by radial ball bearings 83 and 84; 86 is a rotary drive source (motor) fixed to the crankshaft 85 with a key 87, which is fixed to the penetrating portion 300c; As a result, the transmission member 200 makes small reciprocating movements up and down. still,
The axis of the crankshaft 85 is disposed perpendicular to the axis of the main shaft 3.

Reference numeral 303 denotes a cross roller slide, which is installed oppositely into the spindle head 300 and which is connected to the transmission member 2.
It supports small up and down reciprocating movements of 0.00. or,
By fixing the eccentric ring 90 to the crank pin 85b of the crankshaft 85 at an arbitrary position with bolts 92, the eccentricity 85a of the crankshaft 85 can be adjusted.
can be changed to a new arbitrary eccentricity 90a (see FIG. 2).

Therefore, while the main shaft 3 is being rotated by the rotational drive source 15, the crankshaft 85 is rotated by the other rotational drive source 86.
When the main shaft 3 rotates, the main shaft 3 makes a small reciprocating motion up and down via the transmission member 200. At the same time, the spindle head 300 undergoes a large reciprocating movement up and down due to the rotation of the other rotary drive source 51. In this way, while the grindstone 1 is grinding the workpiece W, large and small reciprocating movements are superimposed.

Note that by transmitting a small vertical reciprocating motion to the main shaft 3 via the transmission member 200, it is possible to improve the rotational accuracy of the main shaft 3 and further speed up the rotation. Moreover, according to this small reciprocating device, it is possible to easily set an arbitrary vertical stroke and the number of vertical movements per unit time.

The diameter expansion mechanism of the grindstone 1 is composed of a differential gear mechanism 150, a reversible rotation drive source 156, a second gear 164, a sliding metal fitting 163, and the like.

153 is a first gear fixed to the main shaft 3.
Reference numeral 152 denotes an input gear that meshes with the first gear 153, and is fixed to one input shaft 151 that is pivotally supported by the spindle head 300. 154 is a second gear 1 that is screwed into a screw 3f screwed into the intermediate portion of the main shaft 3.
64, which is an output gear that meshes with the spindle head 300.
The input shaft 155 is loosely fitted to the other input shaft 155 which is directly connected to a reversible rotation drive source 156 disposed therein. A differential gear mechanism 150 is disposed between one input shaft 151 and the other input shaft 155. Reference numeral 160 is a grinding wheel diameter expanding rod having a tapered part 160a formed at the tip (lower end) in order to slightly expand the machining diameter of the grinding wheel 1, and is inserted into the main shaft 3 through the horn 2, and held in a predetermined position by a coiled compression spring 190. is maintained. 161
is a push-down rod of the grindstone diameter expansion rod 160 and is inserted into the main shaft 3. 163 is thrust ball bearing 1
65, which is freely suspended from the second gear 164 by a bearing holder 167, and clamps the push-down rod 161 through a notch window 3g formed in the axial direction of the main shaft 3 by a bolt 162. are doing.

Therefore, the rotational drive source 15 causes the main shaft 3 to make small reciprocating movements up and down during vertical rotation, and at the same time,
Since the splines (not shown) of the grindstone diameter expanding rod 160 are engaged with the splines (not shown) of the horn 2, the grindstone 1 also rotates. On the other hand, pulley 13
The rotation of the input gear 152 meshing with the first gear 153 integrated with is transmitted to the output gear 154 via one input shaft 151 and the differential gear mechanism 150,
This causes the second gear 164 to rotate. At this time, the second gear 164 rotates at the same speed as the main shaft 3 at a predetermined position on the threaded portion 3f of the main shaft 3, and moves as the main shaft 3 moves in a small up-and-down reciprocating manner. Note that this small vertical reciprocating motion is a motion in the tooth width direction of the second gear 164 and the output gear 154, and therefore is not transmitted to the output gear 154. Reversible rotation drive source 15
When the other input shaft 155 is rotated by 6, the rotation speed of the output gear 154 changes according to the difference in the rotation speed between one input shaft 151 and the other input shaft 155.
The rotation speed of the second gear 164 and the main shaft 3 are adjusted accordingly.
When there is a difference in the number of rotations of the two gears, and the former is larger than the latter, the second gear 164 is rotated and lowered due to the screw pair. As a result, the push rod 16
1. The grinding wheel expanding rod 160 descends and the rotating grinding wheel 1
is pushed out in the radial direction by the tapered portion 160a, so the working diameter of the grindstone 1 is expanded and the workpiece W can be cut. Note that when the number of rotations of the second gear 164 is made smaller than the number of rotations of the main shaft 3, the second gear 164 rises while rotating, contrary to the above.

By providing the grindstone diameter expansion mechanism in this way,
During the grinding process using a suitable number of whetstones 1, those whetstones 1
The machining diameter can be expanded to the required machining diameter.

Note that the present invention is not limited to the configuration of the above-described embodiments; for example, the slide ball bearing may be a brane bearing, a hydraulic or pneumatic hydrostatic bearing, or a magnetic bearing. In addition, the cross roller slide is a hydraulic or pneumatic pressure control slide,
It may also be a magnetic slide.

Further, as shown in FIG. 4, the grindstone diameter expansion mechanism includes a reversible rotation drive source 156 disposed on the same axis as the main shaft 3, a cutting screw member 141 provided between the main shaft 3, and a push-down rod. 161 can be replaced with one that moves up and down.

This reversible rotation drive source (motor) 156 is fixed on the same axis as the pulley 13, and a threaded thread 3k is threaded on the inner circumferential surface of the upper end of the main shaft 3, and a threaded member 141 for cutting is screwed into this threaded thread 3k. ing. Further, a spline portion 141a is carved in the axis of the cutting screw member 141, and a reversible rotation drive source 156
A spline shaft 156a fixed to the spline shaft 156a is inserted therethrough. A pulley shaft 34 is fixed to the pulley 13, and is pivotally connected to a bearing housing 37 fixed to the headstock 301 via a tapered roller bearing 36. 161 is the cutting screw member 14
It is a push-down rod protruding downward from the center of the lower surface of the grinding wheel 1, and is in contact with the grindstone diameter expanding rod 160 inserted into the main shaft 3. Reference numeral 142 denotes a coiled compression spring fitted onto the push-down rod 161, and its elastic urging force urges the cutting screw member 141 upward via a thrust ball bearing 143. 147 is a support member fixed to the headstock 301;
146 is a brush insulatively fixed to the support member 147, and 156b is a current collector ring insulatively fixed to the pulley 13.

Therefore, while the main shaft 3 is rotating as described above,
The cutting screw member 1 is driven by the reversible rotation drive source 156.
41 moves up and down without rotating. When the cutting screw member 141 descends, the grindstone diameter expansion rod 160 descends within the main shaft 3 via the push-down rod 161. As a result, the rotating grindstone 1 is pushed out in the radial direction by the tapered portion 160a, so that the machining diameter of the grindstone 1 is expanded and the workpiece W can be cut.

Furthermore, the same effect can be obtained even if the male ball screw is a normal screw or one that provides reciprocating movement to the spindle head using a mechanism such as a cam.

<Effects of the Invention> As explained above, in this invention, the whetstone attached to the horn rotates and grinds the inner circumferential surface of the workpiece, while the small up and down reciprocating motion is consistent with the machining length of the workpiece. As a result of superimposing large vertical and reciprocating movements,
Compared to conventional methods, it achieves excellent roundness with high efficiency, has low cutting resistance and does not generate heat from the workpiece, and excellent grinding precision can be stably obtained regardless of whether the machining diameter is small or large. It has the effect of being In addition, the main shaft of the present invention performs a small vertical reciprocating motion via a transmission member by a small vertical reciprocating device,
The inertial force associated with this becomes extremely small, allowing for stable reciprocating motion at high speeds.

Further, since the present invention includes a grindstone diameter expansion mechanism made of a differential gear mechanism, the diameter of the grindstone can be expanded at any time while the main shaft is rotating at an arbitrary number of rotations or while the main shaft is stopped. Therefore, even if the dimensional difference between the workpiece before and after processing is large, it can be easily accommodated. Furthermore, by quickly expanding the diameter of the grindstone when it wears out, the precision of the workpiece can be easily controlled and the processing efficiency can be improved.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of the present invention;
The figure is a partially enlarged front view of the crankshaft that provides small up-and-down reciprocating motion, Figure 3 is a plan sectional view, Figure 4 is a reference sectional view showing another grinding wheel diameter expansion mechanism, and Figure 5 is a conventional lap device. The sectional view, FIG. 6, is an enlarged explanatory view of the eccentric tire shown in FIG. 5. 1...Whetstone, 2...Horn, 3...Main shaft, 15
... Drive device (rotary drive source), 50... Ball male screw (large reciprocating device), 51... Rotating drive source, 85... Crankshaft (small vertical reciprocating device), 86... Rotating drive source, 150...Differential gear mechanism (grindstone diameter expansion mechanism), 156...Reversible rotation drive source, 163...Sliding metal fitting, 164...Second gear, 200...Transmission member, 300...Spindle head, 3
02...Column.

Claims (1)

[Scope of Claims] 1. A spindle head supported by a vertically extending column so as to be movable up and down; a transmission member sharing an axis within the spindle head and supported so as to be movable up and down; and the transmission member. a main shaft rotatably installed in the main shaft; a horn having an appropriate number of grindstones disposed at the lower end of the main shaft and equipped with a grindstone diameter expansion mechanism; and a drive device that drives the main shaft to rotate the horn. and an arm having a ball female screw threaded in the vertical direction and protruding from the side of the spindle head, and an arm provided parallel to the axis of the spindle and screwed into the ball screw of the arm. the spindle head is reciprocally moved in the axial direction of the spindle to drive a horn provided at the lower end of the spindle. It has a large up-and-down reciprocating device that moves the workpiece up and down by a distance commensurate with the processing area of the workpiece, and a crankshaft that is disposed on the spindle head and perpendicular to the axis of the spindle. a small vertical reciprocating device that rotates the main spindle through the transmission member to make a small reciprocating movement up and down with a distance corresponding to the machining area as an upper limit of amplitude; A grinding wheel expansion rod having a tapered portion and movable coaxially and axially within the main shaft, an input gear connected to a pair of input shafts, and an input gear connected to the input gear. a differential gear mechanism including an output gear that meshes with a planetary gear and outputs the revolution of the planetary gear as rotation; a gear mechanism that transmits rotation of a main shaft to one input shaft of the differential gear mechanism; a reversible rotation drive source that can rotate the other input shaft of the differential gear mechanism in forward and reverse directions; a second gear that slides against the second gear, follows the movement of the second gear in the axial direction, and has a bolt at one end for transmitting the movement; a sliding metal fitting that is provided to allow vertical movement of the grinding wheel expanding rod through a notch window provided in the main shaft; A precision finishing honing machine characterized by being configured such that a grinding wheel diameter expanding rod descends to enlarge the machining diameters of the appropriate number of grinding wheels.