CN214685212U

CN214685212U - Portal milling machine

Info

Publication number: CN214685212U
Application number: CN201990000694.5U
Authority: CN
Inventors: 马塞洛·马尔切蒂
Original assignee: Ince Bell Aldi Society Pte Ltd
Current assignee: Ince Bell Aldi Society Pte Ltd
Priority date: 2018-05-14
Filing date: 2019-05-10
Publication date: 2021-11-12
Anticipated expiration: 2029-05-10
Also published as: ES1259504Y; WO2019220286A1; DE212019000284U1; ES1259504U; IT201800005332A1

Abstract

The portal milling machine (10) is provided with a pair of uprights (14, 16), and for each upright (14, 16) there is provided a worm (32) and a screw (34), an upper electric motor (40) at an upper end (36) which is directly or indirectly engaged with the screw (34), and a lower electric motor (42) at a lower end (42) which is directly or indirectly engaged with the screw (34).

Description

Portal milling machine

Technical Field

The utility model relates to a field of large machine tool. Specifically, the utility model relates to a gate-type mills machine.

Background

These machines are generally used in the production of large parts, such as parts of nuclear power plants, or parts for the oil and gas industry, or parts for the railway industry, which require very strict manufacturing tolerances for design and reliability reasons.

On the other hand, during machining, the enormous forces occurring in different ways cause deformations of the machine parts, which have a negative effect on the tolerances that can be determined.

Depending on the type of machine, there are different solutions intended to limit the influence of the machining forces on the machine.

In particular, for portal milling machines, there are solutions that use ropes and pulleys to compensate for the deformations undergone by the uprights, or solutions that use some hydraulic pistons to achieve the same purpose.

However, each of these solutions has drawbacks. For example, mechanical systems are bulky and subject to relatively rapid wear, while hydraulic systems require special power supply circuits.

SUMMERY OF THE UTILITY MODEL

The object of the utility model is to provide a large-scale gate-type milling machine, this gate-type milling machine can satisfy the demand of trade and overcome simultaneously for the shortcoming mentioned of prior art.

This purpose is achieved by the door-type milling machine provided by the utility model. The portal milling machine is provided with: a pair of uprights spaced apart in a transverse direction, wherein each upright has a main extension in a respective vertical direction; and a cross member extending in a transverse direction, the cross member being supported by the uprights, the cross member being adapted to slidably support the tool holder head; vertical movement means engaged with the cross member to drive translation of the cross member in a vertical direction; wherein for each upright, the vertical movement means comprises a screw supported by the upright, the screw extending along a vertical screw axis parallel to the vertical direction between an upper end and a lower end, the screw being operatively engaged with the cross member; and wherein, for each upright, the vertical movement means comprise, at the upper end, an upper electric motor directly or indirectly engaged with the screw and, at the lower end, a lower electric motor directly or indirectly engaged with the screw.

Drawings

The features and advantages of the portal milling machine according to the invention will appear more clearly from the following description, made by way of illustrative and non-limiting example with reference to the accompanying drawings, in which:

figure 1 shows an apparatus comprising a portal milling machine according to an embodiment of the present invention;

figure 2 shows the portal milling machine of figure 1;

figure 3 shows an upright of the portal milling machine of figure 2;

figure 4 shows a vertical section of the uprights of figure 3 with cross members and vertical displacement means.

Detailed Description

With reference to the figures, the reference numeral 1 generally designates a machine tool device comprising a base 2, which base 2 is formed generally below ground level, in which base 2 the worktables 4 of the portal milling machine are arranged in parallel along a longitudinal direction X.

For example, each table 4 includes a pair of table guides 4'.

The machine tool apparatus 1 further comprises a portal milling machine 10, the portal milling machine 10 comprising a pair of vertical carriers 12, each vertical carrier 12 being slidably engaged with a respective work table 4.

The milling machine 10 further comprises a pair of

uprights

14, 16 spaced apart along a transverse direction Y orthogonal to the longitudinal direction X, wherein each upright 14, 16 has a main extension along a respective vertical direction W1, W2.

Each upright 14, 16 is supported by a respective vertical carrier 12 and preferably has a box-like structure provided with stiffening plates to ensure high rigidity.

Each upright 14, 16, preferably with quadrangular section, has a front face 17, on which front face 17 parallel vertical guides 18 are applied, extending in vertical directions W1, W2.

Preferably, said vertical guides 18 only partially occupy the front face 17, while the remaining part houses the vertical movement means 30, as will be discussed below.

The milling machine 10 further comprises a cross member 20, which cross member 20 extends in the transverse direction Y and is slidably engaged with said vertical guide 18 on each upright 14, 16.

The milling machine further includes a tool holder head slidably supported by the cross member and a milling tool supported by the tool stabilizer head.

The vertical movement means 30 of the milling machine 10 are engaged with the cross member 20 to drive the translation of the cross member 20 along the vertical directions W1, W2.

For each upright 14, 16, the vertical movement means 30 comprise a worm 32 applied to the cross member 20 and combined with the cross member 20. For example, on the rear face 20b opposite to the front face 20a intended to apply the tool holder head, the cross member 20 has an attachment 22 to which the worm 32 is mechanically connected.

Said vertical moving means 30 further comprise an endless ball screw 34, the endless ball screw 34 being rotatably engaged with the worm 32, the endless ball screw 34 having a main extension between the upper end 36 and the lower end 38 along a vertical screw axis Q, which is parallel to the vertical directions W1, W2.

The vertical movement device 30 further comprises an upper electric motor 40 at the upper end 36, which is directly or indirectly engaged with the screw 34, and a lower electric motor 42 at the lower end 38, which is directly or indirectly engaged with the screw 34.

According to one embodiment, each

electric motor

40, 42 is supported by a respective upright 14, 16.

Furthermore, according to a preferred embodiment, said vertical movement means 30 comprise an upper rotatable support 44 and a lower rotatable support 46, the upper rotatable support 44 rotatably supporting the upper end 36 of the screw 34, the lower rotatable support 46 rotatably supporting the lower end 38 of the screw 34.

Preferably, the upper and lower

rotatable supports

44, 46 are adapted to accommodate a plurality of ball circulation bearings for optimally supporting the screw 34.

Furthermore, preferably, an upper rotatable support 44, a lower rotatable support 46 are applied to the front face 17 of the

respective uprights

14, 16.

Further, preferably, the upper electric motor 40 is coaxial with the lower electric motor 42 and aligned with the vertical screw axis Q of the screw 34.

The milling machine 10 further comprises an electronic screw control device 100, which electronic screw control device 100 is used to control the operation of the

motors

40, 42 of each upright 14, 16 to obtain a controlled rotation of the screw 34.

In particular, said screw control device, comprising a PLC or a microprocessor programmed by suitable software, is configured or programmed to perform torque control according to master/slave logic, wherein, for example, for each upright 14, 16, the upper electric motor 40 acts as a torque control driving member and the lower electric motor 42 acts as a torque control driven member.

Furthermore, it is preferred that the screw control device does not employ any preloading, since the mechanical constraints between the motors implemented by the screws are sufficiently rigid and free of play.

Furthermore, the screw control preferably distributes the torque equally between the two motors.

Furthermore, the milling machine 10 comprises an electronic lateral control device 110, which electronic lateral control device 110 is used to keep the cross member 20 from twisting dynamically or statically.

The electronic lateral control device 110, which comprises, for example, a PLC or a microprocessor programmed by suitable software, is configured or programmed to operate the position control between the

motors

40, 42 of the first upright 14 and the

motors

40, 42 of the second upright 16 according to master/slave logic.

For example, in the electronic lateral control device 110, the upper electric motor 40 of the first upright 14 operates as a driving member in terms of position control, while the upper electric motor 40 of the second upright 16 operates as a driven member in terms of position control.

For the above purpose, the milling machine 10 comprises means for detecting the position of the cross-member; for example, the detection means comprise two optical circuits specularly mounted on one upright and on the other upright, and are adapted to send signals representative of the position of the cross-member 20 on the respective upright 14, 16 to the electronic transverse control means 110.

Of course, displacement of the tool holder head along the cross member 20 involves an imbalance in the load on the two pairs of

motors

40, 42.

The electronic cross control 110, by means of the control of the position, allows the overall activity requirement to keep the cross member straight during its ascent or descent between the two uprights, while within each upright the electronic screw control 100 equally distributes the torque between the two motors.

Innovatively, the portal milling machine according to the present invention overcomes the drawbacks mentioned with respect to the prior art, since it allows to significantly increase the apparent (apparent) stiffness of the screw, thus improving the precision of the displacement of the cross member.

Furthermore, advantageously, the presence of two motors for each screw increases the reliability of the machine, since the two motors achieve redundancy in terms of support of the screws, which is useful in the event of failure or damage to one of the two motors of the screw.

It is clear that a person skilled in the art can make modifications to the milling machine described above to satisfy contingent needs, all of which are within the scope of protection of the claims defined above.

Claims

1. A portal milling machine provided with:

-a pair of uprights (14, 16) spaced apart along a transverse direction (Y), wherein each upright (14, 16) has a main extension along a respective vertical direction (W1, W2); and

-a cross member (20) extending along said transverse direction (Y), said cross member (20) being supported by said uprights (14, 16), said cross member (20) being adapted to slidably support a tool holder head;

-vertical movement means (30), said vertical movement means (30) being engaged with said cross member (20) to drive the translation of said cross member (20) along said vertical direction (W1, W2);

-wherein, for each upright (14, 16), the vertical movement means (30) comprise a screw (34) supported by the upright (14, 16), the screw (34) extending along a vertical screw axis (Q) parallel to the vertical direction (W1, W2) between an upper end (36) and a lower end (38), the screw (34) being operatively engaged with the cross member (20); and

-wherein, for each upright (14, 16), the vertical movement means (30) comprise, at the upper end (36), an upper electric motor (40) directly or indirectly engaged with the screw (34) and, at the lower end (38), a lower electric motor (42) directly or indirectly engaged with the screw (34).

2. Gantry milling machine according to claim 1, wherein for each stand the upper electric motor (40) and the lower electric motor (42) are supported by the stand (14, 16).

3. Gantry milling machine according to claim 1, wherein said screw (34) is of the recirculating ball type.

4. Gantry milling machine according to claim 2, wherein said screw (34) is of the recirculating ball type.

5. Door milling machine according to claim 3 or 4, wherein the vertical movement means (30) comprise, for each upright (14, 16), an upper rotatable support (44) and a lower rotatable support (46), the upper rotatable support (44) rotatably supporting the upper end (36) of the screw (34), the lower rotatable support (46) rotatably supporting the lower end (38) of the screw (34), the upper rotatable support (44) and the lower rotatable support (46) being adapted to house a plurality of endless ball bearings.

6. Gantry milling machine according to any one of claims 1 to 4, wherein the upper electric motor (40) is coaxial with the lower electric motor (42) and the upper electric motor (40) is aligned with the vertical screw axis (Q) of the screw (34).

7. Gantry milling machine according to any one of claims 1 to 4, comprising an electronic screw control device (100) for controlling the rotation of the screw (34).

8. Gantry milling machine according to claim 7, wherein for each upright (14, 16) the electronic screw control device (100) is configured or programmed to perform torque control according to master/slave logic.

9. Door milling machine according to claim 8, wherein the upper electric motor (40) acts as a torque control drive and the lower electric motor (42) acts as a torque control follower.

10. The portal milling machine of claim 8 wherein the electronic screw control distributes torque equally between the two motors.

11. Gantry milling machine according to any one of claims 1 to 4, wherein it comprises an electronic lateral control device (110), said electronic lateral control device (110) being used to detect the arrangement of the lateral members, either dynamically or statically.

12. The door milling machine of claim 11, wherein the electronic lateral control device (110) is configured or programmed to operate position control between a motor of a first one of the uprights and a motor of a second one of the uprights according to master/slave logic.

13. Door milling machine according to claim 12, wherein within the electronic lateral control device (110) the upper electric motor (40) of the first stand operates as a driving member in terms of position control, and the upper electric motor (40) of the second stand operates as a driven member in terms of position control.

14. Gantry milling machine according to claim 12, wherein it comprises means for detecting the position of the cross member (20), said means for detecting the position of the cross member (20) being operatively connected to the electronic lateral control means (110).

15. Gantry milling machine according to claim 14, wherein for each upright (14, 16) the detection means comprise an optical scale, which is mirror-mounted.