JPH0413088B2 - - Google Patents

Description

[Detailed Description of the Invention] "Field of Industrial Application" This invention is a lead screw nut used in the sliding drive unit of the blade mount of various types of blades for cutting in automatic lathes with moving headstock. Concerning a mechanism loading device.

``Prior technology'' A moving headstock automatic lathe, which is one of the automatic lathes for bar processing, consists of a main shaft that chucks and rotates the bar material, and a sliding motion on the bed to give this main shaft linear movement in the axial direction. A moving head stock, a tool post that can be moved in a direction perpendicular to the sliding direction of the head stock, various types of cutting tools such as bits and drills that are attached to this tool post and that cut the above-mentioned bar material, and a bar. The main structure consists of a guide bush that supports the workpiece near the processing position and prevents the workpiece from being bent or deformed due to cutting.

That is, the bar chucked by the spindle and subjected to rotational motion is fed in the axial direction by the sliding motion of the headstock, and is cut by a predetermined cutter attached to the tool rest.

Therefore, since a guide bushing is used,
It has high rigidity against cutting force and is suitable for precision machining of long and thin parts.Furthermore, secondary machining such as horizontal hole drilling, keyway machining, and back machining can be performed with a single lathe by using various attachments. It has the following characteristics.

An example thereof will be explained with reference to FIGS. 2 to 4.

FIG. 2 shows a side view of a numerically controlled automatic lathe.

A long rod-shaped workpiece 1, several meters long, is passed through the headstock 2 from the rear, gripped firmly by the chuck 3 of the spindle, and the tip of the workpiece is hemmed to the top of the bed 4 with high rigidity. The bushing stand frame 5 is also penetrated.

At the same time, the headstock 2 is linearly fed by a drive mechanism system of a numerically controlled servo motor 6, and at the same time, tool rests 7A to 7E arranged radially on the front of the bushing frame 5 with the workpiece 1 at the center and the cutters attached thereto are moved. 8A to 8E are also sequentially fed by a drive mechanism system of numerically controlled servo motors 9, 9, so that the workpiece 1 can be consistently cut with high efficiency.

If you look at the front of the pushbutton stand in more detail, the third
As shown in the figure.

In the figure, a total of five tool rests 7A to 7E are installed radially around the workpiece 1, with two sets of left and right tools facing each other. The configuration is such that it is driven by.

Using tool holders 10 attached to the tool rests 7A to 7E, necessary types of cutlery 8A to 8E are mounted with accurate centering.

The relational structure between the bushing frame 5 and the tool rests 7A to 7E is clearly shown in FIG. A guide bush 11 is attached to prevent rotational wobble.

Although details of the drive mechanism have been omitted, the output of the servo motor 9 is transmitted to the feed screw shaft 12, which is fixed to a parent nut 13 that forms a ball screw pair, and a slider 14 that can slide with high precision in the axial direction. Then, a large-diameter pin 15 or 16 protruding from the slider 14 is brought into contact from behind an L-shaped block 18 fixed to the bottom surface of each of the tool rests 7A to 7D, which are arranged in a pair facing each other. The two turrets 7a, 7D or 7B, 7E are individually fed using two types of forward and reverse rotation of the servo motor 9.

Reference numeral 19 in FIG. 4 is a compressed coil spring for back-moving the tool rest.

In the above example, all of the plurality of machining members are always located on the machining work line, and can perform the machining work as they progress.

As mentioned above, automatic lathes with a moving headstock are generally configured to rotatably support the vicinity of the cutting part of the bar material rotated at high speed by the main spindle with a guide bushing, thereby preventing the bar material from being bent and deformed during machining. ing.

In the above-mentioned Figures 2 to 4, the plurality of machining members (cutters) are all positioned in advance on the machining work line, so there is no need for indexing, and the machining work can be performed by advancing. In contrast, in contrast to the conventional method, in which the processing members are arranged in a row and the mounting base of the equipment itself can be moved toward and away from the workpiece by the advancing and retracting mechanism, the processing members are There are 4 locations on the mounting base: a processing position and a non-processing standby position.
If it is possible to change the position alternately, processing,
A single advancing/retracting mechanism is sufficient for moving the non-processing position.
The applicant proposed a new mechanism in Japanese Patent Application Laid-Open No. 117700/1983 because the space would be significantly degraded.

The gist of this is that one of the two piston rods installed in a separate double-barrel cylinder block is used for both the slider, which serves as the mounting base for processing members such as cutting blades, and the slide base, which serves as the slide guide base for the slider. The piston rod is fixed to the slider side, and the cylinder block is movable relative to the slider to two extreme positions corresponding to the stroke of the piston rod, and the other piston rod is fixed to the slider side, and the slider is moved relative to the cylinder block. The point is that the slider can be moved to the ultimate position corresponding to the stroke of the piston rod, and in the end, the slider can be moved to four different positions with respect to the slide base.

Hereinafter, this will be explained in detail based on FIGS. 5 to 8.

Figures 5 a to d are a half-sectional front view, left side view, and right side view of the mechanism as seen with the slider attached to the lid removed, a view in the direction of arrows d to d in figure a, and Figures 6 a to d.
d is a view of the four-position position of the lifting mechanism, and FIG. 7 is a view of the installation of the slider equipped with the processing member.

In the figure, reference numeral 21 denotes a twin cylinder block having cylinders 21a and 21b, which is assembled into a storage groove 22a cut in the slide base 22 in such a manner as to cover the slide base 22 and the groove 22a. The slider 23 is arranged in a separate state without contacting both sides as described below.

The cylinders 21a and 21b each have a piston 2
4, 25 and cylinder lids 26, 26', 27,
27', and although the mutual strokes may be different, the cylinder volumes must be designed to be identical in order to achieve synchronous operation.

A cylinder lid 26 holding the piston 24 is held by an oil supply sleeve 28 fixed to the slide base 22, and a cylinder lid 26' on the opposite side is held by an oil supply sleeve 29 fixed to the slide base 22.

A position adjustment screw 3 is attached to one end of the piston 24.
0 is attached, and this is fixed to a bracket 31 fixed to the slider 23.

Thus, the piston 24 and the slider 23 are in an integral relationship.

On the other hand, the other end of the piston 24 is connected to the cylinder lid 2.
It hits against the position adjustment screw 32 provided at the tip of 6'.

One end of the piston 25 is fixed to the slide base 22 by a cylinder positioning collar 33 and a cylinder fixing nut 34.

Thus, the piston 25 and the slide base 22 are in an integral relationship.

On the other hand, the other end of the piston 25 is held by a hollow position adjustment screw 35 screwed into the slide base 22.

Therefore, the cylinder block 21, which is separated from both the slide base 22 and the slider 23 and is floating in the groove 22a, is connected to the piston 2.
5, it is moved back and forth by that stroke.

As a result, the cylinder lid 26 slides within the oil supply sleeve 28, and the cylinder lid 26' slides within the oil supply sleeve 29 together with the cylinder block 21 by the same stroke.

With the above configuration, the combination of the two extreme positions and postures of the pistons 24 and 25 allows the slider 23 to be placed in four positions as shown in FIGS. 6a to 6d.

In the diagram above, the cylinders 21a, 2
The oil passages A to D (shown as filled in) connected to both ends of cylinder block 21 constitute the main mechanism such as the oil supply sleeve, cylinder cover, and piston rod without using the usual means of connecting flexible hoses to both ends of cylinder block 21. It is said that the paired members are carved with a design that can accommodate relative displacement, but this allows each paired member to be set at the same temperature, eliminating the reduction in operating accuracy due to expansion differences. be done.

In addition, cylinder block 2 is the largest heating element.
1 is in a floating state in the groove 22a as described above, separated from the slide base 22 and the slider 23, so there is a heat insulating space and there is no heat transfer, which is preferable because it avoids the inconvenience caused by heat transfer and expansion. .

FIG. 7 shows an embodiment in which the slider 23 equipped with the cutting blades 36a to 36e is covered with the cutting mechanism.

In the figure, an arrow 37 indicates a direction in which the slide table 22 moves forward and backward, and an arrow 38 indicates a direction in which the slider 23 moves.

In addition, 39 and 39' in Fig. 7 are the slide base 2.
This is the advance/retreat guide liner for No. 2.

Next, each position in FIGS. 6a to 6d will be explained in detail.

In other words, () In position [1], oil passages A and D
Lubricate the bracket 31 with the oil supply sleeve 28.
Position adjustment screw 4 installed in a position that hits the
Perform position adjustment using 0.

() In position [2], oil passages A and C
Lubricate and adjust the position using the position adjustment screw 32.

() In position [3], oil passages B and D
Lubricate and adjust the position using the position adjustment screw 35.

() In position [4], oil passages B and C
Lubricate and adjust the position using the position adjustment screw 30.

Therefore, each position can be adjusted, and by switching the oil path, position selection can be performed easily and stably from any position, and can be quickly selected to move toward the ultimate position at the same speed. .

Furthermore, near the limit, the oil escape path becomes a bottleneck, increasing resistance, and has the advantage of automatically braking to prevent shock from occurring.

A simplified version of FIG. 6 is shown in FIG. 8a.

In this figure, the stroke of the piston 24 is set to twice the stroke β of the piston 25, and four equally spaced positions shown in figure b are shown.

For example, let the stroke of the piston 24 be α(≠2β,
>β), the position is as shown in figure C [2]
It is possible to widen the gap between and [3].

The ninth embodiment is such that the advance/retreat guide liners 39, 39' are inclined to the bush frame.
Shown in Figures a and b.

According to this, since the sliding base 22 is always given the downward force of its own weight, the sliding base 22 moves in the same direction.
The movement of the tool 2 is smooth and requires only a small driving force, and it is rational that the reaction force during cutting can be absorbed by its own weight.

In the figure, 43 is a servo motor for driving the slide table 22 forward and backward, 44 is a lead screw/nut mechanism using a ball screw and nut equipped to the servo motor 43, and 45 is a lead screw/nut mechanism that may be added to the lead screw/nut mechanism 44. 1 shows a loading device of the present invention.

By the way, the cutting blades 36a to 36e are positioned at four positions according to the above-mentioned configuration, and the movement of the slide table 22 performs diameter-changing cutting on the material to be processed.

Further, 3 disposed on the opposite side facing the 36a.
6e begins processing under the positioning of 36a.

In other words, a total of five cutting blades can be operated.

In the figure, reference numeral 41 indicates a guide bush frame, and reference numeral 42 indicates a guide bush.

``Problems to be Solved by the Invention'' As is clear from the above-mentioned Figures 2 to 4 or 5 to 9, the lead screw nut mechanism is commonly used as a mechanism for advancing and retracting the turret due to its smoothness. However, there is an inconvenience that the inertia force is large and the speed must be reduced in order to control the stop at a predetermined position.

In particular, in the configuration shown in FIG. 9 above, if there is no device such as the loading device 45 of the present invention in the advance/retreat drive section of the slide base 22, the lead screw
Due to the nut mechanism, a large inertial force is generated and the weight is also added, making it difficult to stop at a predetermined position, and eventually the speed must be reduced significantly.

However, this does not allow the slide platform 22 to move to a predetermined position.
A quick sliding movement cannot be achieved, resulting in a decrease in operating speed and low efficiency.

"Means for Solving Problems" and "Operation" The present invention was made in view of the above circumstances, and its gist is that a load screw is attached to the ball screw of the lead screw/nut mechanism, and A timing belt or the like is used to transmit power between the ball screw and the load screw, and a pair of load nuts, which are movable toward and away from each other and are prevented from rotating and are assembled via an elastic spring, are engaged with the load screw. Assembling the ball screw in a load sleeve so as to be slidable in the axial direction and prevented from rotating, the load force that suppresses the inertia force on the ball screw can be easily adjusted, and a load device that can be constructed in a small space is constructed and operated. The point is that it is possible to eliminate the decrease in speed.

"Example" This will be explained in detail below based on the drawings.

1A and 1B are longitudinal sectional views of the loading device 45 added to the lead screw/nut mechanism 44 introduced in FIG. 9, and a view taken along arrows A to A in FIG. 1A.

Note that the loading device 45 in this figure is installed in an opposite position from that in FIG. 9b.

The lead screw nut mechanism 44 is constructed as follows.

That is, a coupling ring 47 is disposed on the servo motor 43 assembled to a motor bracket 46 fixed to the guide bush frame 41, and a ball screw 48 is coupled to the coupling ring 47.

In the illustrated example, a coupling pin 47a is attached to a coupling pulley 50 fixed to a ball screw 48 with a fixing pin 49, and a coupling pin 47a is protruded from the coupling ring 47.
are connected by interlocking.

Bearing holder 5 is attached to motor bracket 46.
There is a bearing 53 fixed by 1 and 52, and a ball screw nut 55 is fixed to a ball screw bracket 54 fixed to the slide base 22.

Furthermore, a bearing receiver 56 is disposed on the ball screw bracket 54 to support a bearing 57. The ball screw 48 is connected to the bearing 5 described above.
3. It is supported between the ball screw nut 55 and the bearing receiver 56.

With the configuration described above, the rotational power of the servo motor 43 is transmitted to the ball screw 48, and the ball screw 48 connects the ball screw bracket 54, that is, the slide base 22.
It slides.

The loading device of the present invention added to the lead screw/nut mechanism 44 described above is as follows.

That is, a load screw 58 is installed inside and attached to a load sleeve 59 fixed to the guide bush frame 41 with respect to the ball screw 48 .

The interior configuration includes a pair of road nuts 60,6
This is done through acceptance via 1.

The pair of load nuts 60 and 61 is configured such that the smaller diameter load nut 60 can be accommodated in the protruding outer skin part 61a of the larger diameter load nut 61, and both are connected via an elastic spring 62 and are attached to the outer surface of the load nut 60. Engraved slide groove 6
A detent pin 63 protruding from the load nut 61 is engaged with 0a so that they can be moved toward and away from each other and are integrally biased to rotate.

On the other hand, a detent pin 64 protruding from the load sleeve 59 is engaged with a slide groove 61b formed on the outer surface of the load nut 61.

Thus, the pair of load nuts 60 and 61 are rotated by the load screw 58 and the load sleeve 59 is rotated.
The load nuts 60 and 61 slide in the axial direction while being prevented from rotating inside, but at this time, a biasing force is applied by the resilient spring 62 to the pair of load nuts 60 and 61 that are integrally restrained so that they tend to separate from each other. As a result, the load screw 58 is assembled as if both legs were pressed against it, generating a large frictional resistance, that is, a load.

The above component can be made compact by designing the lead of the load screw 58 to be smaller than the lead of the ball screw 48.

65 and 66 are bearings that cover the front and rear of the load sleeve 59.

A load pulley 68 is fixed to the tip of the load screw 58 by a fixing pin 67, and a timing belt 69 is stretched between the load pulley 68 and the coupling pulley 50 to transfer the rotational movement of the ball screw 48 to the load screw. I'm telling 58.

[Effects of the Invention] As described above, according to the loading device of the present invention, the loading force can be easily adjusted by the elastic spring 62, and by designing the lead of the loading screw 58 to be small, a compact structure can be achieved.

Based on these advantages, the operating speed of the lead screw/nut mechanism can be increased, which is extremely suitable.

Furthermore, when the present invention is adopted in the lead screw nut mechanism 44 that uses dead weight as shown in FIG. This is preferable because it allows the lead screw/nut mechanism to be utilized while retaining the advantage of using its own weight.

[Brief explanation of drawings]

Figures 1a and 1b are longitudinal cross-sectional views showing an example of mounting the product of the present invention, views from A to A in Figure a, Figures 2 to 4 are explanatory diagrams of an example of a headstock sliding type automatic lathe, Figures 5 to 8
The figure is an explanatory diagram of the 4-position position selection mechanism proposed by the present applicant in a previous application, and FIGS. 9a and 9b are tables of a guide bush frame of an automatic lathe with a moving headstock equipped with the 4-position position selection mechanism. It is a back view. 58...Load screw, 59...Load sleeve, 60...Load nut, 60a...Slide groove, 61...Load nut, 61a...Protruding outer skin part, 61b...Slide groove, 62...Elastic spring, 63... Rotating pin, 64... Rotating pin, 65, 66... Bearing, 67...
Fixed pin, 68...Load pulley, 69...Timing belt.

Claims (1)

[Scope of Claims] 1. A load screw is provided alongside the ball screw of the lead screw/nut mechanism, and transmission is transmitted between the ball screw and the load screw using a timing belt or the like, and the load screws can be moved toward and away from each other and are prevented from rotating; A lead characterized in that a pair of load nuts assembled through an elastic spring are engaged with each other, and the pair of load nuts are further assembled into a load sleeve so as to be slidable in the axial direction and prevented from rotating. Loading device with screw nut mechanism. 2. The installation target is a slider as a mounting base for a cutting blade and a slide base as a slide guide base for the slider, and one of the two piston rods equipped on a twin cylinder block with a separate configuration is fixed to the slide base side. The cylinder block can be moved to two extreme positions corresponding to the stroke of the piston rod with respect to the slide base, and the other piston rod is fixed to the slider side, so that the slider can be moved to the extreme position corresponding to the stroke of the piston rod with respect to the cylinder block. In the end, the slider can be moved to four different positions with respect to the slide base 4
Position Selection Mechanism The lead screw of the sliding drive unit of the tool mount is assembled to the advance/retreat guide liner, which is constructed by tilting the slide table to the button frame to assemble the headstock movable automatic lathe to the button frame. - The loading device according to claim 1, which is a nut mechanism.