Polishing head

Abstract

The present invention describes a polishing head (1) comprising a first flange (2) for connection to a drive shaft; a protective housing (3) comprising an engagement element (31) operably connected to the drive shaft for transmitting rotational motion about a corresponding axis (X) to the protective housing (3); a plurality of tool clips (4) positioned to protrude below the housing (3); and a motion transmission device (5) designed to convert the rotational motion into oscillation of the tool clips (4) about their own axis (Y) transverse to the axis (X).

Description

Technical Field

[0001] This invention relates to a polishing head.

[0002] In particular, the present invention relates to a hydraulic polishing head with a oscillating tool holder.

[0003] These polishing heads are particularly suitable for polishing machines and / or grinding machines that process marble, granite, limestone, volcanic rock, or any other stone. Background Technology

[0004] Currently, polishing heads used for stone grinding and polishing in existing technologies generally include a vertical axis, which is connected to a corresponding motor unit on one side and to a housing on the other side, so that the housing rotates at a predetermined speed.

[0005] There is a fixed reaction flange between the housing and the shaft receiving moving parts. This flange is supported by the housing by means of a bearing, the axis of which is parallel to the axis of the shaft.

[0006] The housing supports multiple tool clamping elements, to which corresponding grinding tools can be connected. These tool clamping elements are controlled to oscillate around their respective axes by means of a mechanical transmission device connected to the drive shaft, so that each grinding tool provides oscillating motion around the axis of its corresponding clamping element and rotational motion around the axis of the drive shaft.

[0007] There are currently several methods for kinematic connections that transmit motion from the spindle to different tool holders.

[0008] For example, a cam with a suitable shape (such as a tubular cam) can be used.

[0009] Furthermore, there are embodiments employing special connecting rods, levers, or rockers equipped with rollers that interact with corresponding cam mechanisms.

[0010] Due to the shape of the transmission device, the use of the above-mentioned prior art components may cause uneven oscillation of the tool holder. When the continuous rotational motion of the drive shaft is converted into the alternating motion of each driven shaft, the transmission device may generate dead points or acceleration.

[0011] These phenomena negatively impact the polishing process.

[0012] There are also some existing polishing heads that achieve the oscillating motion of the tool holders by means of a motion transmission device consisting of multiple gears (pivoting on the corresponding tool holders).

[0013] While it overcomes the shortcomings of the previously mentioned solution, this solution can certainly be improved, and conversely, it also has some drawbacks.

[0014] The first drawback of polishing heads with gear transmission is that they do not allow for easy adjustment of the oscillation frequency of the tool holder.

[0015] In fact, the gears must be replaced in order to adjust the frequency.

[0016] Another drawback is that these existing technology heads do not always guarantee optimal response to wear.

[0017] Another drawback of these existing technologies is that they do not always guarantee fully optimized energy consumption.

[0018] In reality, most of the energy supplied is dissipated due to friction.

[0019] Another drawback is that these existing polishing heads are not always simple and inexpensive to manufacture.

[0020] Examples of known polishing heads are described in EP0510603A2 and EP0667210A1. Summary of the Invention

[0021] Therefore, the object of the present invention is to provide a polishing head that overcomes the above-mentioned disadvantages of the prior art.

[0022] Another object of the present invention is to provide a polishing head that allows for easy change of the oscillation frequency of the tool holder, thereby enabling convenient adjustment of the performance of the polishing head as required.

[0023] Another object of the present invention is to provide a polishing head that provides adequate responsiveness in terms of wear resistance and optimized energy consumption.

[0024] Another object of the present invention is to provide a polishing head that is simple to manufacture and inexpensive.

[0025] According to the present invention, the above and other objectives can be achieved by a polishing head comprising the technical features described in the appended claims. Attached Figure Description

[0026] With reference to the foregoing objectives, the technical features of the present invention are clearly described in the appended claims, and the advantages of the invention will become more apparent from the following detailed description, in which the accompanying drawings illustrate purely non-limiting exemplary embodiments of the invention:

[0027] - Figure 1 This is a perspective side view of the polishing head according to the present invention, viewed from above.

[0028] - Figure 2 It's viewed from above. Figure 1 A three-dimensional side view of the cross-section of the polishing head;

[0029] - Figure 3 It's viewed from below. Figure 1 A side view showing the details of the polished head;

[0030] - Figure 4 It's viewed from below. Figure 1 A three-dimensional view of a portion of the hydraulic head;

[0031] - Figure 5 Is with Figure 4 The same view, rotated by an angle to show the other parts;

[0032] - Figure 5b yes Figure 5 A magnified view of the details;

[0033] - Figure 6 The position of piston 73 as a function of time t is shown on a rectangular coordinate plane;

[0034] - Figure 7 The position of piston 74 as a function of time t is shown on a rectangular coordinate plane. Detailed Implementation

[0035] Reference Figure 1 The number 1 generally represents the polishing head manufactured according to the present invention, and is also referred to as head 1 below.

[0036] The head 1 includes a first flange 2 for connecting the drive shaft of a corresponding motor device.

[0037] The head 1 according to the invention also includes a box-shaped outer shell 3.

[0038] Advantageously, the housing 3 is connected to the first flange 2, such that the first flange 2 is inserted between the housing 3 and the aforementioned motor device.

[0039] The outer shell 3 includes an upper portion 3', a lower portion 3”, and an internal volume V.

[0040] Advantageously, the upper part 3' and the lower part 3" are fixed to each other by a plurality of bolts.

[0041] Advantageously, the internal volume of the outer casing 3 is filled with oil.

[0042] In addition, the housing 3 also includes a coupling element 31 operably connected to the drive shaft for transmitting rotational motion about the corresponding axis X to the housing 3.

[0043] Advantageously, the coupling element 31 is formed on the upper portion 3' of the housing 3.

[0044] The head 1 according to the invention includes a plurality of tool clips 4, which are mounted on the lower portion 3” in a manner that protrudes from below the housing 3.

[0045] Advantageously, refer to Figure 1 and Figure 2 The tool holder 4 is positioned on the perimeter of the lower part 3” of the outer casing 3.

[0046] Advantageously, the tool holder rotates together with the entire housing 3.

[0047] Advantageously, tool holder 4 includes a grinding tool.

[0048] These grinding tools are designed to engage with stone for polishing and buffing.

[0049] The grinding tools can be removed from the corresponding tool holder 4, allowing them to be replaced at the end of their service life.

[0050] The head 1 also includes a motion transmission device 5 located in the internal volume V of the housing.

[0051] The transmission device 5 is located in an oil bath.

[0052] The transmission device 5 is designed to convert the rotational motion (provided to the housing 3 via the drive shaft) into a lateral swing of the tool holder 4 around the corresponding Y-axis in relation to the X-axis.

[0053] Advantageously, each polishing tool is designed to engage with the stone to polish and buff it using a combination of rotation around the X-axis and oscillation around the Y-axis.

[0054] The motion transmission device 5 includes a plurality of levers 6 which are operatively connected to each tool holder 4, and each lever 6 includes a first lever 61 and a second lever 62.

[0055] The transmission device 5 also includes a linear actuation hydraulic device 7 consisting of a first piston 73 and a second piston 74.

[0056] Advantageously, the hydraulic device 7 includes a pair of first hydraulic cylinders 71 and second hydraulic cylinders 72.

[0057] Advantageously, the first piston 73 and the second piston 74 are designed to translate within the first hydraulic cylinder 7 and the second hydraulic cylinder 72 in a direction parallel to the axis X, respectively.

[0058] More advantageously, each pair of first hydraulic cylinders 71 and second hydraulic cylinders 72 are positioned along the X-axis close to their respective levers 6.

[0059] Pistons 73 and 74 can move between a first descending position and a second ascending position, and come into contact with the first lever 61 and the second lever 62, respectively.

[0060] Specifically, when pistons 73 or 74 are in the lowered position, they apply force to their respective first lever 61 or second lever 62.

[0061] On the other hand, when piston 73 or 74 is in the raised position, the corresponding first lever 61 or second lever 62 applies a force to piston 73 or 74.

[0062] The motion transmission device 5 also includes a hydraulic circuit 8, which is designed to supply linear actuation hydraulic devices 7.

[0063] The hydraulic circuit 8 is configured to alternately pressurize and depressurize the first piston 73 and the second piston 74, such that all the first pistons 73 are in the lowered position and all the second pistons 74 are in the raised position, and vice versa.

[0064] In particular, such as Figure 6 and Figure 7 As shown, at each instant t (t1, t2, t3, t4...), each first piston 73 pushes on the corresponding first lever 61 of each lever 6 to impart rotation R to each tool holder 4, while at each instant t+Δt (t1+Δt, t2+Δt, t3+Δt...), each second piston 74 pushes on the corresponding second lever 62 of each lever 6 to impart rotation R' to each tool holder 4.

[0065] Advantageously, each repetition of these rotations R and R' defines the swing of the tool holder 4 around the Y-axis.

[0066] Reference Figure 6 and Figure 7 At each instant t, piston 73 is in the descending position and piston 74 is in the ascending position, while at each instant t+Δt, piston 74 is in the descending position and piston 73 is in the ascending position.

[0067] Reference Figures 3 to 5 The hydraulic circuit 8 includes a hydraulic pump 81, which is designed to draw oil from the internal volume V of the housing 3 and introduce it into the circulation of the hydraulic circuit 8.

[0068] Advantageously, such as Figure 3 As shown, the housing 3 includes a toothed portion 32 formed inside the upper portion 3', which is designed to mesh with a gear 811 of the pump 81 to actuate the pump 81.

[0069] Advantageously, the gear 811 is mounted on the pump 81.

[0070] According to another embodiment, pump 81 is driven by a battery or a motor.

[0071] Advantageously, the hydraulic circuit 8 includes a first branch and a second branch.

[0072] The first branch is connected to the first piston 73, and the second branch is connected to the second piston 74.

[0073] When pump 81 is operated, at least one of the first and second branches is under pressure, while the other branch is depressurized.

[0074] According to another embodiment not shown, the hydraulic circuit 8 includes a hydraulic pump for each branch, so that each branch can be actuated individually.

[0075] The hydraulic circuit 8 also includes a distributor 82, which is designed to receive oil from the pump 81.

[0076] The distributor 82 includes a valve 822 with an automatic reversing function, which is configured to alternately pressurize the first branch and the second branch.

[0077] Specifically, valve 822 with automatic reversing function is configured to pressurize the branch until the grinding tool comes into contact with the stone to be polished and / or sanded.

[0078] When the grinding tool comes into contact with the stone, valve 822 reverses its action, thereby pressurizing another branch until the same situation occurs as before.

[0079] The first branch and the second branch respectively include a first manifold 83' and a second manifold 83 connected to the distributor 82.

[0080] Advantageously, the first manifold 83” and the second manifold 83” include an oil flow rate regulator 833.

[0081] Also advantageously, the flow rate regulator 833 is designed to regulate the oil flow rate inside the hydraulic circuit 8, so as to adjust the oscillation frequency of the grinding tool as needed.

[0082] Specifically, the interval Δt between each piston (73, 74) from the rising position to the falling position (and vice versa) depends on the oil flow rate value and can be adjusted by means of the flow rate regulator 833.

[0083] The upper portion 3' includes a second reaction flange 33, which is designed to dampen vibrations.

[0084] Advantageously, the second reaction flange 33 is inserted between the first flange 2 and the upper portion 3' of the outer casing 3.

[0085] Furthermore, advantageously, the second flange 33 is made of an elastic material.

[0086] The hydraulic circuit 8 includes a filter 84 for removing impurities from the circulating oil.

[0087] The polishing head according to the present invention overcomes the above-mentioned disadvantages and brings important advantages.

[0088] The first advantage is that the polishing head 1 designed according to the present invention ensures a significant reduction in the risk of wear due to its special operating structure.

[0089] In fact, the polishing head 1 is simple to manufacture, allowing for minimal contact between mechanical parts, thereby reducing the possibility of wear and damage.

[0090] Furthermore, minimizing contact between mechanical parts greatly reduces friction and thus reduces energy dissipation.

[0091] Therefore, the polishing head 1 of the present invention also has the advantage of providing a product that can optimize energy consumption.

[0092] Another advantage of the polishing head 1 according to the invention is that the oscillation frequency can be adjusted without changing the structure of the head.

Claims

1. Polishing head (1), comprising: - A first connecting flange (2) is used to connect the head (1) to the drive shaft of the corresponding motor device; - A protective housing (3) with a box-shaped structure, the protective housing including an upper portion (3'), a lower portion (3'') and an internal volume (V), the protective housing (3) including a coupling element (31) operatively connected to the drive shaft to transmit rotational motion about its own axis (X) to the protective housing (3). - Multiple tool clips (4) are disposed on the lower portion (3'') and protrude below the protective housing (3); - A transmission device (5), disposed in the internal volume (V) of the housing (3) and used for transmitting motion, and configured to convert the rotational motion into an oscillation of the tool holder (4) about its own axis (Y) transverse to the axis (X). The transmission device (5) for transmitting motion includes: - Multiple levers (6), said levers being operatively connected to each of said tool holders (4), each lever including a first lever (61) and a second lever (62), the polishing head (1) being characterized in that it comprises: - A linear actuation hydraulic device (7), the linear actuation hydraulic device comprising a first piston (73) and a second piston (74), the pistons (73, 74) being movable between a first descending position and a second ascending position, the pistons (73, 74) respectively contacting the first lever (61) and the second lever (62); wherein, in the descending position, the pistons (73, 74) apply force on their respective levers (61, 62); and in the ascending position, the corresponding levers (61, 62) apply force on the pistons (73, 74); - A hydraulic circuit (8) configured to supply the linear actuation hydraulic device (7); the hydraulic circuit (8) is configured to alternately pressurize and depressurize the first piston (73) and the second piston (74), such that all the first pistons (73) are alternately in the lowered position and all the second pistons (74) are in the raised position, and vice versa.

2. The head (1) as described in claim 1, characterized in that, The internal volume (V) of the protective casing (3) is filled with oil.

3. The head (1) as described in claim 2, characterized in that, The hydraulic circuit (8) includes a hydraulic pump (81) designed to draw oil from the internal volume (V) of the protective housing (3) and circulate the oil in the hydraulic circuit (8).

4. The head (1) as described in claim 3, characterized in that, The protective housing (3) includes an internal toothed portion (32) formed on the upper portion (3'), the toothed portion being designed to engage with a gear (811) of the hydraulic pump (81) to drive the hydraulic pump (81).

5. The head (1) as described in any one of claims 3-4, characterized in that, The hydraulic circuit (8) includes a first branch and a second branch, the first branch being connected to the first piston (73) and the second branch being connected to the second piston (74).

6. The head (1) as described in claim 5, characterized in that, The hydraulic circuit (8) includes a distributor (82) configured to receive the oil from the hydraulic pump (81), and the distributor (82) includes an automatic directional valve (822) configured to alternately pressurize the first branch and the second branch.

7. The head (1) as described in claim 6, characterized in that, The first branch and the second branch include a first manifold (83') and a second manifold (83'') respectively connected to the distributor (82), and the first manifold (83') and the second manifold (83'') include a regulator (833) for the flow rate of the oil.

8. The head (1) as described in any one of claims 1-4, characterized in that, The upper portion (3') includes a second reaction flange (33) configured to dampen any vibration.

9. The head (1) as described in claim 2, characterized in that, The hydraulic circuit (8) includes a cleaning filter (84) for cleaning impurities in the circulating oil.

10. The head (1) as claimed in any one of claims 1-4, characterized in that, The tool holder (4) includes a grinding tool.

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