JPS62152673A - Grinding machine - Google Patents

Abstract

PURPOSE:To prevent pulling-in phenomena of a work and make possible accurate creep grinding of the work by mounting a hydraulic cylinder for moving a movable table to the same direction as a work feed direction during down cut grinding. CONSTITUTION:When down cut grinding is performed by the feed of a creep feed means 16, discharge oil from a hydraulic pump 25 is branched to the third oil passage 31 side and the second hydraulic cylinder 18 side from a branch point on the second oil passage 23. Hydraulic fluid having pressure controlled with a relief pressure control valve 33 on the third oil passage 33 flows in the cylinder chamber of the second hydraulic cylinder 18. Thereby, a piston rod 18a is pushed out, and a movable table 3 is moved to the same direction as the moving direction of the piston rod 18a by the force according to the pressure of the hydraulic fluid. Thereby, backlash between a pinion 15 and a rack 12 in the creep feed means 16 is removed and pulling-in phenomena of a work w is prevented, and grinding accuracy of the work w is increased.

Description

[Detailed Description of the Invention] Object of the Invention (Industrial Application Field) The present invention relates to a grinding machine, and particularly relates to a grinding machine configured to perform creep grinding by deep cutting of a grindstone and minute feed of a workpiece. It is something.

(Prior art) Generally, in a grinding machine capable of creep grinding, a screw mechanism such as a Bohne screw or a gear mechanism such as a rack or pinion is provided between a movable table and a driving means such as a manual or motor. As shown in FIG. 5, there is up-cut grinding in which the movable table 3 is slightly fed in the opposite direction to the rear of the rotation of the grinding wheel 11, and as shown in FIG. Down-cut grinding is performed by slightly feeding forward in the direction of rotation.

(Problems to be Solved by the Invention) By the way, in the above-described up-cut grinding, the direction in which the workpiece W is fed by the gear mechanism 16 and the direction in which the workpiece W is rotated by the grindstone 11 are opposite to each other. 1
Although there is no risk of the work W being pulled in due to the backlash of 6, during down cut grinding, the direction in which the work W is fed by the gear mechanism 16 and the direction of rotation of the grindstone 11 are the same, so the gear The workpiece W is likely to be pulled in due to backlash between the pinion 15 of the mechanism 16 and the rack 12. The overload associated with this pulling phenomenon may cause burns on the grinding surface or even damage the grindstone.

Structure of the Invention (Means for Solving the Problems) This invention has been made by focusing on the above-mentioned problems, and includes a sliding guide body 1 supported on a grinding machine frame, and a sliding guide body 1 supported by a grinding machine frame. The workpiece W is slidably supported on the grinding wheel 1.
1, a hydraulic cylinder 17.18 for reciprocating the movable table 3 during normal grinding, and a hydraulic cylinder 17.18 connected to the movable table 3 via a screw or gear mechanism 12.15. , a creep feed means 16 for reciprocating the movable table 3 during creep grinding;
is sent in the forward direction with respect to the rotation direction of the grindstone 11,
A hydraulic circuit 19 is provided to operate the hydraulic cylinder 18 so that a pressing force is applied to the movable table 3 in the same direction as the moving direction of the movable table 3.

(Function) Therefore, in the grinding machine of the present invention, when performing down cut grinding by applying forward feed to the workpiece W with respect to the rotational direction of the grindstone 11 by the creep feed means 16,
Since the movable table 3 is pressed in the same direction as the feeding direction of the workpiece W by the operation of the hydraulic cylinder 18, the creep feed means 16 has one screw or gear mechanism 12.1.
The backlash of No. 5 is reliably removed, and the phenomenon of drawing in the workpiece W is prevented.

(Example) Hereinafter, an example in which the present invention is embodied in a surface grinder will be explained with reference to the drawings.

As shown in Fig. 1.2, a saddle 1 as a sliding guide is supported on a grinding machine frame (not shown) so as to be able to reciprocate in the Y direction (direction perpendicular to the plane of the paper in Fig. 1). A pair of guide grooves 2 extending opposite each other are recessed in the side surfaces. A movable table 3 is disposed on the saddle 1, and a convex portion 4 formed at the lower part of both sides of the table 3 and the guide groove 3 of the saddle 1 are arranged.
By fitting with the saddle 1, it is possible to reciprocate and slide along the longitudinal direction of the saddle 1, that is, the X direction (the left-right direction in FIG. 1).

A plurality of groove-shaped oil pockets 6 are formed on each of the sliding surfaces 5 on the upper, side, and lower surfaces of the convex portion 4 so as to extend in the sliding direction.

Each oil pocket 6 communicates via an orifice 7 with an oil supply passage 9 that is fixed to the movable table 3 and connected to a pump (not shown), thereby generating static pressure 1! +F4
8, and the pressure oil supplied to each oil pocket 6 causes static pressure to act on each sliding surface 5 of the movable table 3.

A workpiece W is held on the upper surface of the movable table 3 via an electromagnetic jack 10 so as to face a grindstone 11 . This grindstone 11 is supported via a grindstone head (not shown) so as to be able to be lowered in the R direction to a column of the grinding machine, and is driven to rotate clockwise in FIG. 1 by a motor (not shown).

A rack 12 is fixed to one end surface of the movable table 3 so as to extend in the sliding direction of the movable table 3. A motor 13 equipped with a speed reduction mechanism and capable of forward and reverse rotation is disposed near the rack 12, and a pinion 15 that can be engaged with and released from the rack 12 is attached to its output shaft.

A manual operation handle (not shown) is connected to the binion 15, and the binion 15 can be rotated by selectively driving the handle and the front TD motor 13. A creep feed means 16 is constituted by the rack 12, the pinion 15, the motor 13, the manual operation handle, etc., and when the rack 12 and the pinion 15 are engaged, the motor 13 can be rotated in the normal direction or the handle can be rotated in one direction. When the pinion 15 is rotated in the direction of the arrow in FIG. Up-cut creep grinding is performed on the workpiece W with the notch provided. Furthermore, when the pinion 15 is rotated in the direction of the arrow in FIG. The workpiece W is minutely fed in the forward direction, and the workpiece W is subjected to down-count creep grinding by the grindstone 11.

On the other hand, a pair of hydraulic cylinders 17.
18 is fixed, the piston rod 17a of one first hydraulic cylinder 17 faces the one end hanging wall 3a of the movable table 3 from inside in a state of being uncoupled, and the piston rod 18a of the other second hydraulic cylinder 18 is fixed. The other end of the movable table 3 is connected to the inner surface of the hanging end q3b. When pressure oil from a hydraulic circuit 19 (described later) is supplied to the blank cylinder of the first hydraulic cylinder 17, the piston rod 17a protrudes, the movable table 3 is moved to the right in FIG. A feed in the opposite direction to the rotational direction of the grindstone 11 is applied to the grindstone 11 .

Also, is the pressure oil in the second hydraulic cylinder 18? When the workpiece W is fed within δ, the screw rod 18a protrudes, the movable table 3 is moved to the left in the figure, and the workpiece W is fed in the forward direction with respect to the rotational direction of the grindstone 11. Therefore, when the rack 12 and the binion 15 are disengaged by the switching mechanism (not shown) and the creep feed means 16 is set to the non-operating state, the first and second
With the alternating operation of the hydraulic cylinders 17 and 18, the movable table 3 is slid back and forth on the saddle 1 at high speed through the action of the static pressure, and the workpiece W is normally ground by rIn by a relatively shallow cut of the grindstone 11. It looks like this.

Next, a hydraulic circuit for alternately operating each of the hydraulic cylinders 17 and 18 and applying a pressing force in the same direction as the moving direction of the movable table 3 via the second hydraulic cylinder 18 during the down cut grinding described above. The configuration of No. 19 will be explained.

A first oil passage 21 extending from the oil supply/drainage port 17b of the first hydraulic cylinder 17 is connected to the B port of a 4-bot, 3-position switching type electromagnetic switching valve 22 that is ABT-connected. A second oil passage 23 extending from the oil supply/drainage port 18b is connected to the A port of the electromagnetic switching valve 22. A hydraulic pump 25 driven by a motor 24 is connected to the P boat of the electric Fi1 switching valve 22, and is configured to suck the ura in the ura tank 27 through a filter 26. An oil drain passage 28 is connected to the T-boat of the electromagnetic switching valve 22, and the check valve 2
It is open to the oil tank 27 via 9. Further, a relief valve 30 is provided between the P port 1 of the electromagnetic switching valve 22 and the hydraulic pump 25.

When the electric switch valve 22 is switched to one position 22a, the oil discharged from the hydraulic pump 25 is transferred to the first oil path 22a.
1 to the first hydraulic cylinder 17, and as its piston rod 17a protrudes, the movable table 3 slides to the right in FIG. 1, and as the piston rod 18a of the second hydraulic cylinder 18 retracts. As a result, the oil in the cylinder chamber flows through the second oil passage 23, the electromagnetic switching valve 22, and the drain oil passage 28.
and is discharged into the oil tank 27 via the check valve 29.

Further, when the electromagnetic switching valve 22 is switched to the other position 22b, the discharge oil of the hydraulic pump 25 is supplied to the second hydraulic cylinder 18 via the second oil passage 23, and the movable table is moved by the protrusion of the piston rod 18a. 3 is moved to the left in FIG. Oil drain path 2
8 and the check valve 29 to the oil tank 27. The operating pressures of both the first and second hydraulic cylinders are adjusted as appropriate by changing the set pressure of the relief valve 30.

On a third oil passage 31 disposed between the second oil passage 23 and the oil tank 27, a two-position switching type one-way control valve 32 and a relief valve 33 capable of adjusting the set pressure are connected in series. has been done. Then, as shown in Fig. 1.3, the one-way control valve 3
2 is switched to one position ft232a, the built-in reverse ratio valve causes the flow from the second oil passage 23 to the third oil passage 23.
The outflow of oil to the oil passage 31 side is closed, and the third oil passage 31 is opened when the one-way control valve 32 is switched to the other position 32b as shown in FIG. There is. Therefore, when the electromagnetic switching valve 22 is switched to the other position 22b while the third oil passage 31 is open, the oil discharged from the hydraulic pump 25 is transferred between the second oil passage 23 and the third oil passage 31.
The hydraulic oil branches into the oil passage 31 and flows into the second oil passage 31, and the hydraulic oil at the pressure adjusted in advance by the relief valve 33 on the third oil passage 31 flows into the second oil passage 31.
It acts on the screws 1 to 1 of the hydraulic cylinder 18, and a pressing force in the same direction as the feed direction by the creep feed means 16 acts on the movable table 3 through the protrusion of its piston rod.

Next, the operation of the grinding machine configured as above will be explained.

Now, Figure 1 shows the state during normal grinding.
Assuming that the rack 12 and the pinion 15 in the creep feed means 16 are M rBed to each other, the hydraulic circuit 1
The one-way control valve 332 in 9 closes the third oil passage 31 (located in the i7 stomach).

In this state, when the hydraulic pump 25 is driven, the discharged oil is alternately supplied to the first hydraulic cylinder 17 and the second hydraulic cylinder 18 in accordance with the switching operation of the electromagnetic cutoff (φ valve 22). 17.18 piston rod 17a,
The movable table 3 is placed on the saddle 1 by the protrusion of 18a.
is reciprocated in the X direction at high speed, and the workpiece W is ground with a relatively shallow cut by the grindstone 11. At this time, the movable table 3 is supported in a floating state on the saddle 1 by the action of static pressure, so the sliding resistance is extremely reduced and the movable table 3 is moved smoothly with a small driving force. Furthermore, since feed in both directions is provided by separate single-rod type hydraulic cylinders 17 and 18, the pawl/knockin resistance is halved compared to the case where double-rod type double-acting cylinders are used, and the movable table 3 is It can be sent even more smoothly.

FIG. 3.4 shows a state in which the work W is creep-ground by applying a minute feed by the creep feed means 16 and a relatively deep cutting suspension by the grindstone 11. In FIG. FIG. 4 shows up-cut grinding in which the work W is sent in the opposite direction to the rotation direction of the grindstone 11, and FIG. 4 shows down-cut grinding in which the work W is sent in the forward direction to the rotation direction of the grindstone 11.

During up-cut grinding, as shown in FIG. 3, the binion 15 of the creep feed means 16 engages with the rack 12, and the one-way control valve 32 of the hydraulic circuit 19 closes the third oil passage 31, and the electromagnetic The switching valve 22 is in the neutral position.
It is held at no. In this state, when the pinion 15 is rotated clockwise in the figure by the motor 13 or the manual operation handle (not shown), the movable table 3 is slightly fed in six directions in the figure via the rack 12, and the grindstone 11 The workpiece W is ground by the grinder. At this time, the piston rod 18a of the second hydraulic cylinder 18 is retracted as the movable table 3 moves, but the packing resistance of the second hydraulic cylinder 18 is extremely small, and the cylinder chamber is connected to the second oil passage 23, the electromagnetic Eight-to-toe connection of switching valve 22 and oil drain path 2
Since the movable table 3 is opened to atmospheric pressure via the movable table 8, the resistance value of each part that resists the movement of the movable table 3 is slightly reduced, and smooth micro-feeding can be performed.

In addition, since the piston rod 17a of the first hydraulic cylinder 17 is not connected to the movable table 3, the piston rod 17a does not follow the movement of the movable table 3 and is held at the retracted position during the first cutting with the first cut. , no resistance force is applied to the feeding of the movable table 3. In addition, during up-cut grinding, as shown in FIG. 5, since the feeding direction of the workpiece W and the r11 cutting direction of the grindstone 11 are opposite, backlash occurs between the rack 12 and the pinion 15 in the creep feed means 16. There is no risk of this occurring. Therefore, by the actions of each part described above, up-cutting with creep can be performed with extremely high precision.

On the other hand, when performing downcut grinding by feeding the creep feed means 16, the one-way control valve 32 of the hydraulic circuit 19 opens the third oil passage 31, and the electromagnetic switching valve is held at the other position 22b. In this state, when the binion 15 is driven counterclockwise in the figure, the movable table 3
is in the forward direction with respect to the rotation direction of the grindstone 11 (left side in Fig. 4)
, and the workpiece W is ground by the grindstone 11 . At this time, the oil discharged from the hydraulic pump 25 is
3rd Ura Road 31 side and 2nd hydraulic cylinder 18 from the upper branch point
Hydraulic oil flows into the cylinder chamber of the second hydraulic cylinder 18 at a pressure adjusted in advance by the relief valve 33 on the third oil passage 31 . Therefore, the piston rod 18a of the second hydraulic cylinder 18 is projected and presses the movable table 3 in the same direction as its moving direction with a force corresponding to the pressure of the hydraulic oil. As a result, as shown by the chain line in FIG.
The tooth surface on the moving direction side of the rack 12 is pressed against the south surface on the opposite rotation direction side, and backlash between the pinion 15 and the rack 12 is eliminated. Therefore, in down-cut grinding in which the workpiece W is sent in the forward direction with respect to the rotational direction of the grindstone 11, even if the grinding surface fluctuation occurs due to variations in the abrasive grains of the grindstone 11 or unevenness on the machined surface of the workpiece W, conventional Therefore, there is no fear that the movable table 3 will suddenly protrude in the direction of movement of the movable table 3 and the workpiece W will be pulled in, and the accuracy of grinding the workpiece W can be dramatically improved. Note that during down-cut grinding, the piston rod 17a of the first hydraulic cylinder 17 is held in the retracted position, as in the above-mentioned up-cut grinding, so it is likely that this will act as a drag force against the movement of the movable table 3. That's not it.

Note that the present invention is not limited to the configuration of the embodiment described above, and for example, the creep feed means 16 may be replaced with the rack 12 and the pinion 15 described above, and may be replaced with a gear of a worm and a worm wheel, or a ball screw. It is also possible to change the structure of each part arbitrarily and to embody it, for example, by using a screw RfM including a screw RfM, etc., without detracting from the spirit of the present invention.

Effects of the Invention As described in detail above, according to the present invention, the creep feed means feeds the workpiece in the forward direction relative to the rotational direction of the grinding wheel to perform downcutting (~grinding). Since the work is pressed in the same direction as the feed direction of the work by the operation of the hydraulic cylinder, the backlash of the screw or screw machine hη in the creep feed means is reliably removed, and the work is prevented from being pulled in and the work is moved. The excellent effect of being able to grind creep in Gaojing 1st Hall is to attack the Song Dynasty.

[Brief explanation of drawings]

Fig. 1 is a front view of a grinding machine showing an embodiment of the present invention in normal ω1 cutting direction, Fig. 2 is a partially cutaway side view showing the support 1.11 configuration of a machi vj table, and Fig. 3 is a front view of a grinding machine showing an embodiment of the invention. ωI showing up cut grinding shape r during creep grinding
A front view of f'ill W'A, Fig. 4 is a front view of the grinder showing the down cut grinding state during creep grinding, and Fig. 5 is a part showing the operating state of the Gimaru 7 failure mechanism during up cut grinding. Front view, FIG. 6 is a partial front view showing the operating state of the gear mechanism in J5 with 1 cut and 1 with down cut. In the figure, 1 is a saddle as a sliding guide, 3 is a movable table, 8 is a static pressure generating mechanism, 11 is a grindstone, 12.15
16 is a creep feed means, 17 is a first hydraulic cylinder, 18 is a second hydraulic cylinder, 19 is a hydraulic circuit, 22 is an electromagnetic switching valve,
32 is a one-way Ill valve, 33 is a relief valve, and W is a workpiece. Patent applicant: Asase Co., Ltd. Suesho representative person
Patent Attorney On 1) 1 (νSen Figure 1 j I 2 Figure fi 8 Figure 4

Claims (1)

[Claims] 1. A sliding guide (1) supported by the grinding machine frame, and a workpiece (1) slidably supported by the sliding guide (1).
A movable table (3) that holds the W) in a state facing the grindstone (11), hydraulic cylinders (17, 18) that reciprocate the movable table (3) during normal grinding, and the movable table (3). Screw or gear mechanism (12, 1
5), which feeds the movable table (3) back and forth during creep grinding; and the creep feed means (16) moves the movable table (3) in the rotational direction of the grindstone (11). and a hydraulic circuit (19) that operates the hydraulic cylinder (18) so that a pressing force in the same direction as the moving direction acts on the movable table (3) when the movable table (3) is sent in the forward direction. A grinding machine featuring: 2. A static pressure generating mechanism (8) is provided between the sliding guide (1) and the movable table (3) for applying static pressure by pressure oil to the movable table (3). A grinding machine according to claim 1. 3. The hydraulic cylinder moves the movable table (3) to the grindstone (
A first single-rod hydraulic cylinder (17) that sends the movable table (3) in a direction opposite to the rotational direction of the grindstone (11); The grinding machine according to claim 1 or 2, characterized in that it is composed of two hydraulic cylinders (18). 4. The hydraulic circuit (19) alternately operates both the first and second hydraulic cylinders (17, 18) during the normal grinding, and operates only the second hydraulic cylinder (18) during the creep grinding. The grinding machine according to claim 3, characterized in that it includes a switching valve (22) for controlling the grinding machine. 5. The hydraulic circuit (19) has a setting between the switching valve (22) and the second hydraulic cylinder (18) for adjusting the working pressure of the second hydraulic cylinder (18) during the creep grinding. Grinding machine according to claim 4, characterized in that it comprises a pressure-adjustable relief valve (33). 6. The grinding machine according to claim 3, wherein the first hydraulic cylinder (17) includes a piston rod (17a) that does not follow the movement of the movable table (3) during the creep grinding. .