Electric tool

Abstract

The utility model provides an electric tool. The electric tool comprises a power mechanism; the transmission box comprises a box body, a transmission mechanism connected with the power mechanism and an oil cover arranged on the box body, a transmission cavity is formed in the box body, the transmission mechanism is arranged in the transmission cavity, the box body further comprises an oil injection hole communicated with the transmission cavity, and the oil cover detachably seals the oil injection hole; the oil cover comprises a cover body used for sealing the oil injection hole, an air hole formed in the cover body and communicated with the transmission cavity, an oil storage cavity formed in the outer side of the air hole and communicated with the air hole, and an oil plug arranged in the oil storage cavity, the oil plug is used for absorbing lubricating oil overflowing from the air hole, the oil cover further comprises a pressing plate used for covering the oil storage cavity, and the pressing plate is detachably and fixedly connected with the cover body. The oil plug can guarantee the exhaust effect and inhibit grease leakage at the same time.

Description

Technical Field

[0001] The utility model belongs to the technical field of electric tools, and in particular relates to an electric tool with a ventilation and oil leakage prevention structure. Background Art

[0002] Electric tools require grease lubrication for operation. For hammer and pick tools, grease provides lubrication for the transmission components in the transmission box. Since the transmission process generates huge heat, the pressure in the transmission cavity increases. If the gas cannot be discharged, it will seep out from the clearance of the bearing with grease, causing oil leakage. Grease leakage will cause the electric hammer / electric pick to have weak impact, and even grease will splash onto the operator. Therefore, existing hammer and pick tools usually have air holes for ventilation on the oil cover of the transmission box to balance the internal and external air pressure.

[0003] However, after the existing transmission box has been running for a long time, the lubricating oil will inevitably overflow, causing the lubricating oil to leak out and pollute the outer surface of the oil cover.

[0004] Therefore, it is necessary to improve the prior art to overcome the above defects in the prior art. Utility Model Content

[0005] Therefore, the utility model aims to solve the technical problem that the oil cover pores of the transmission box in the prior art are prone to oil leakage.

[0006] In order to solve the above technical problems, the utility model provides an electric tool, comprising:

[0007] Power mechanism;

[0008] A transmission box, comprising a box body, a transmission mechanism connected to the power mechanism, and an oil cover arranged on the box body, wherein a transmission cavity is formed inside the box body, the transmission mechanism is arranged in the transmission cavity, the box body further comprises an oil filling hole communicated with the transmission cavity, and the oil cover is detachable to close the oil filling hole;

[0009] The oil cap includes a cover body for closing the oil filling hole, an air hole arranged on the cover body and connected to the transmission cavity, an oil storage cavity arranged outside the air hole and connected to the air hole, and an oil plug arranged in the oil storage cavity, the oil plug is used to absorb the lubricating oil overflowing from the air hole, and the oil cap also includes a pressure plate for covering the oil storage cavity, and the pressure plate is detachably fixedly connected to the cover body.

[0010] In one embodiment, the operating frequency of the transmission mechanism is greater than 3800 bpm, the number of the air holes is 1, and the diameter range of the air holes is 0.3-0.7 mm.

[0011] In one embodiment, the operating frequency of the transmission mechanism is less than 3800 bpm, the number of the air holes is two, and the diameter of each air hole ranges from 0.8 mm to 1.2 mm.

[0012] In one embodiment, the diameters of each of the air holes are the same.

[0013] In one embodiment, the two air holes are symmetrically arranged about the center line of the oil cover.

[0014] In one embodiment, the operating frequency of the transmission mechanism is 3900 bpm, the number of the air holes is 1, and the diameter of the air holes is 0.5 mm; or,

[0015] The number of the air holes is two, the operating frequency of the transmission mechanism is 3650 bpm, and the diameter of the air holes is 1 mm.

[0016] In one embodiment, the diameter of the air hole is negatively correlated with the frequency of the transmission mechanism.

[0017] In one embodiment, the diameter of the pores ranges from 0.3 mm to 1.5 mm. Assuming that the total flow area of ​​the pores is S mm 2 , the operating frequency of the transmission mechanism is F bpm, and the ratio of the total flow area S of the pores to the operating frequency F is in the range of 0.5*e -4 ~5*e -4 .

[0018] In one of the embodiments, an internal thread is provided on the inner wall of the oil filling hole, the oil cap includes an external thread connected to the oil filling hole, and the oil cap also includes a flange radially extending to the radial outside of the external thread, the flange presses the upper step surface of the oil filling hole and a sealing ring is provided between the flange and the lower step surface of the oil filling hole.

[0019] In one embodiment, the electric tool is a hammer or pick type electric tool.

[0020] The technical solution provided by the utility model has the following advantages:

[0021] The electric tool provided by the utility model is provided with an oil storage cavity connected to the air hole, an oil plug for absorbing lubricating oil is provided in the oil storage cavity, and the oil storage cavity is covered by a pressing plate fixed to the cover body to cover the oil storage cavity. The oil plug can absorb the lubricating oil overflowing from the air hole and temporarily store the lubricating oil in the oil storage cavity, thereby reducing the risk of grease overflowing while the air hole is exhausted. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 A schematic diagram of the three-dimensional structure of the electric tool provided by the embodiment of the utility model;

[0024] Figure 2 A schematic diagram of the three-dimensional structure of the oil cap provided by the embodiment of the utility model;

[0025] Figure 3 for Figure 1 The schematic diagram of the partial cross-section structure of the electric tool through the oil cover air hole is shown;

[0026] Figure 4 for Figure 1 Another cross-sectional structural diagram of the electric tool shown;

[0027] Figure 5 A schematic diagram of the three-dimensional structure of an oil cap provided by another embodiment of the utility model;

[0028] Figure 6 To adopt Figure 5 The schematic diagram of the partial cross-sectional structure of the electric tool with the oil cap shown is through the oil cap air hole. DETAILED DESCRIPTION

[0029] The technical solution of the utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, rather than all of the embodiments. The utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments of the utility model and the features in the embodiments can be combined with each other without conflict.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the utility model and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0031] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0032] Example 1

[0033] This embodiment provides an electric tool. Figure 1 This is a three-dimensional structural diagram of the electric tool provided by the embodiment of the utility model. Figure 2 This is a schematic diagram of the three-dimensional structure of the oil cap provided by the embodiment of the utility model. Figure 3 for Figure 1 The schematic diagram of the partial cross-section structure of the electric tool through the oil cover air hole is shown. Figure 4 for Figure 1 Another cross-sectional schematic diagram of the electric tool is shown.

[0034] See also Figure 1 and Figure 4 The electric tool 100 includes a main body 40, a handle and a transmission box 10. The main body 40 includes a main housing 41 and a power mechanism 42 disposed in the main housing 41. The power mechanism 42 is connected to the transmission mechanism in the transmission box 10, and is used to drive the transmission mechanism in the transmission box 10 to transmit power. The electric tool 100 also includes a working end 60 for connecting a working head, and the output side of the transmission mechanism in the transmission box 10 is connected to the working head to drive the working head to perform a working task. Specifically, the power mechanism 42 is a motor.

[0035] The electric tool may be a hammer or pick-type tool. This embodiment is described by taking the electric tool 100 as an electric hammer as an example. In other embodiments, the electric tool may also be an electric pick.

[0036] See also Figure 1 As shown, the handle includes a main handle 31 and an auxiliary handle 32. The working end 60 is the front of the electric hammer, and the opposite direction is the rear. The auxiliary handle 32 is arranged in front of the main body 40, and the main handle 31 is arranged behind the main body 40. The auxiliary handle 32, the main body 40 and the main handle 31 are arranged in sequence along the front-to-back direction. The main body with a heavier weight is located between the auxiliary handle and the main handle, so that the grip is more stable and labor-saving when operating the power tool.

[0037] Please combine Figure 1 , 3 and Figure 4The transmission box 10 includes a box body 11, a transmission mechanism 13 and an oil cover 12. A transmission chamber 112 is formed in the box body 11, and the transmission mechanism 13 is arranged in the transmission chamber 112. The transmission mechanism 13 is connected to the power mechanism 42, and is used to convert the input of the power mechanism 42 into an output. The box body 11 also includes an oil filling hole 110 connected to the transmission chamber 112, and the oil cover 12 is detachable to close the oil filling hole 110. The oil cover 12 and the oil filling hole 110 are detachable, and the oil filling hole 110 can be opened by removing the oil cover 12 to add lubricating oil to the transmission chamber 112. During the operation of the power tool 100, the transmission mechanism 13 operates at a high frequency in the transmission chamber 112, generating huge heat, resulting in an increase in the pressure in the transmission chamber 112. If the gas cannot be discharged in time, it will seep out from the clearance of the bearing with lubricating grease, causing oil leakage.

[0038] In order to exhaust the air and prevent the oil from leaking, the utility model improves the structure of the oil cap. Figure 2 and Figure 3 The oil cover 12 includes a cover body 121, an air hole 120 disposed on the cover body 121, an oil storage chamber 122 disposed outside the air hole 120 and communicating with the air hole 120, and an oil plug 123 disposed in the oil storage chamber 122. The cover body 121 is detachably connected to the oil filling hole 110 and is used to close the oil filling hole 110. The air hole 120 is disposed on the cover body 121, one end of which is connected to the transmission chamber 112, and the other end of which is connected to the oil storage chamber 122. The oil storage chamber 122 is non-sealed from the outside. The high-pressure air in the transmission chamber 112 can enter the oil storage chamber 122 through the air hole 120, and further be discharged to the outside through the oil storage chamber 122. The oil plug 123 is disposed in the oil storage chamber 122, and the oil plug 123 is used to absorb the lubricating oil overflowing from the air hole 120, so as to temporarily store the lubricating grease in the oil storage chamber 122 to prevent leakage. The oil plug can be, for example, a wool plug. The oil cover 12 also includes a pressure plate 124 for covering the oil storage cavity 122. The pressure plate 124 is detachably fixedly connected to the cover body 121 to facilitate replacement of the oil plug 123, replacing the oil plug full of oil with a clean oil plug. There is a ventilation gap between the pressure plate 124 and the oil storage cavity 122 to achieve air pressure balance. The pressure plate 124 presses against the outer side of the oil plug 123, thereby positioning the oil plug 123 in the oil storage cavity 122.

[0039] The electric tool provided by the utility model is provided with an oil storage cavity connected to the air hole, an oil plug for absorbing lubricating oil is provided in the oil storage cavity, and the oil storage cavity is covered by a pressing plate fixed to the cover body to cover the oil storage cavity, so as to keep the oil plug in the oil storage cavity. The lubricating oil overflowing from the air hole is absorbed by the oil plug and temporarily stored in the oil storage cavity, so that the exhaust effect can be ensured while inhibiting the leakage of grease.

[0040] For specific embodiments, see Figure 3The pressing plate 124 is detachably fixedly connected to the cover body 121 by screws 125. A through hole is set in the middle of the pressing plate 124, and a screw hole is set at a corresponding position of the cover body 121. The screw 125 passes through the through hole and is inserted into the screw hole. The pressing plate 124 and the cover body 121 can be fastened together by tightening the screw 125. At the same time, the screw 125 can also be withdrawn from the screw hole with the help of a screwdriver, so that the pressing plate 124 and the cover body 121 are released from the fastening connection, the pressing plate 124 can be separated from the cover body 121, the oil storage chamber 122 is opened, and the oil plug 123 can be replaced, thereby maintaining the oil absorption capacity of the oil plug and inhibiting the leakage of grease caused by the saturation of the oil plug.

[0041] In order to prevent grease from leaking from the connection between the cover body and the oil filling hole, a sealing structure is used at the connection between the cover body and the oil filling hole. Figure 2 and 3 As shown, the inner wall of the oil filling hole 110 is provided with an internal thread, and the oil cover 12 includes an external thread 126 connected to the oil filling hole 110, and the oil cover 12 is screwed with the internal thread of the oil filling hole 110 through the external thread 126. The oil cover 12 also includes a flange 127 extending radially to the radial outside of the external thread 126, and the outer end surface of the oil filling hole 110 is formed with two-level step surfaces, the flange 127 presses the upper step surface, and a sealing ring 14 is arranged between the flange 127 and the lower step surface. When the oil cover 12 is screwed and fixed to the oil filling hole 110, the sealing ring 14 is squeezed between the lower step surface and the flange 127 to form a sealed connection. In this way, it is ensured that the lubricating grease will not overflow from between the oil filling hole and the cover body to the outside.

[0042] Take the electric hammer as an example, see Figure 3 and Figure 4 The transmission mechanism 13 includes an eccentric wheel 131, a connecting rod 132, a piston 133, and an impact hammer 135. In the direction of power transmission, the power mechanism 42 is connected to the eccentric wheel 131 through a gear mechanism, driving the eccentric wheel 131 to rotate, the eccentric output end of the eccentric wheel 131 is connected to the first end of the connecting rod 132, and the second end of the connecting rod 132 is connected to the piston 133, driving the piston 133 to reciprocate in the transmission chamber 112, and the impact hammer 135 is located on the side of the piston 133 close to the power output. The piston 135 reciprocates at a high frequency in the transmission chamber 112, which can pressurize the air in the transmission chamber 112, and the impact hammer 135 performs a hammering motion under the action of the air, thereby driving the working head to perform hammering work.

[0043] Since the higher the operating frequency of the transmission mechanism 13, the greater the pressure in the transmission cavity, how to set the appropriate air hole size is related to the air pressure balance and oil leakage prevention in the transmission cavity. The inventor of the utility model found that the diameter of the air hole 120 is negatively correlated with the frequency of the transmission mechanism 13, that is, the higher the operating frequency of the transmission mechanism 13, the smaller the diameter of the air hole 120 should be, in order to effectively prevent grease from leaking out and balance the internal and external air pressures. Specifically, if the frequency of the power mechanism increases by 10% while other conditions remain unchanged, the area of ​​the air hole 120 needs to be adjusted to 30% of the original area to effectively prevent grease from leaking out.

[0044] In a specific embodiment, the diameter of the pores 120 ranges from 0.3 mm to 1.5 mm. Assuming that the total flow area of ​​the pores 120 is S mm 2 , the operating frequency of the transmission mechanism 13 is F bpm, and the ratio of the total flow area S of the air hole 120 to the operating frequency F is in the range of 0.5*e -4 ~5*e -4 Setting the pore size within the above parameter range can effectively prevent grease leakage and ensure stable air pressure in the gear cavity.

[0045] See also Figure 2 In a specific embodiment, the operating frequency of the transmission mechanism 13 is less than 3800 bpm, the number of the air holes 120 is two, and the diameter range of each air hole is 0.8 mm-1.2 mm. An oil storage cavity 122 is arranged outside each air hole 120, and an oil plug 123 is arranged inside the oil storage cavity 122. The pressing plate 124 is in the shape of a circular plate, and its diameter is greater than the maximum width occupied by the two oil storage cavities 122. The pressing plate 124 can cover the two oil storage cavities 122 at the same time, so as to keep the two oil plugs 123 in their respective oil storage cavities 122 synchronously at the same time.

[0046] It should be noted that the above-mentioned “synchronous maintenance” is understood as: the fastening connection of the pressure plate 124 can realize the pressing of the two oil plugs 123 at the same time.

[0047] Furthermore, the diameter of each air hole 120 is the same. The two air holes are set to be of the same size, which can avoid the problem of unbalanced grease leakage caused by a larger air hole size, so that the two oil plugs evenly share the pressure of ventilation and oil leakage prevention.

[0048] Specifically, the operating frequency of the transmission mechanism 13 is 3650 bpm, and the diameter of each air hole 120 is 1 mm, which can effectively prevent grease leakage and achieve ventilation.

[0049] In a specific embodiment, the two air holes 120 are symmetrically arranged about the center line of the oil cover 12, the oil storage cavity 122 is located directly above the air holes 120, and the pressure plate 124 is fixedly arranged at the center of the cover body 121, and the pressure plate 124 covers the oil storage cavity 122. The symmetrical arrangement of the air holes allows the oil storage cavity and the pressure plate to be centered relative to the cover body, and the oil cover structure is more symmetrical and has higher strength.

[0050] Example 2

[0051] The utility model also provides an electric tool. Figure 1 and Figure 6 The electric tool comprises a main body 40, a handle, a working end 60 and a transmission box. The transmission box comprises a housing 11, an oil filling hole 110, a transmission chamber 112 and an oil cover 12'. The structure of the electric tool is basically the same as that of the electric tool described in Example 1, and the difference lies in the pore structure in the oil cover 12'. The same structures and components are marked with the same reference numerals, and can be found in the detailed description of Example 1, which will not be repeated here. The following focuses on the differences.

[0052] See also Figure 5 and Figure 6 As shown, the operating frequency of the transmission mechanism 13 is greater than 3800 bpm, the number of the air hole 120' is 1, and the diameter range of the air hole 120' is 0.3-0.7 mm. The above parameter settings can effectively prevent grease leakage under the premise of achieving ventilation.

[0053] Specifically, the operating frequency of the transmission mechanism 13 is 3900 bpm, the number of the air hole 120 ′ is 1, and the diameter of the air hole 120 ′ is 0.5 mm.

[0054] The air hole parameter setting provided in this embodiment matches the frequency of the transmission mechanism, which can achieve the purpose of preventing oil leakage and balancing air pressure.

[0055] Obviously, the above described embodiments are only a part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, ordinary technicians in this field can make other different forms of changes or modifications without creative work, which should fall within the scope of protection of the utility model.

Claims

1. An electric tool, characterized in that: include: Power mechanism; A transmission box, comprising a box body, a transmission mechanism connected to the power mechanism, and an oil cover arranged on the box body, wherein a transmission cavity is formed inside the box body, the transmission mechanism is arranged in the transmission cavity, the box body further comprises an oil filling hole communicated with the transmission cavity, and the oil cover is detachable to close the oil filling hole; The oil cap includes a cover body for closing the oil filling hole, an air hole arranged on the cover body and connected to the transmission cavity, an oil storage cavity arranged outside the air hole and connected to the air hole, and an oil plug arranged in the oil storage cavity, the oil plug is used to absorb the lubricating oil overflowing from the air hole, and the oil cap also includes a pressure plate for covering the oil storage cavity, and the pressure plate is detachably fixedly connected to the cover body.

2. The electric tool according to claim 1, characterized in that: The operating frequency of the transmission mechanism is greater than 3800 bpm, the number of the air holes is 1, and the diameter range of the air holes is 0.3-0.7 mm.

3. The electric tool according to claim 1, characterized in that: The operating frequency of the transmission mechanism is less than 3800 bpm, the number of the air holes is two, and the diameter of each air hole ranges from 0.8 mm to 1.2 mm.

4. The electric tool according to claim 3, characterized in that: The diameter of each pore is the same.

5. The electric tool according to claim 3, characterized in that: The two air holes are symmetrically arranged about the center line of the oil cover.

6. The electric tool according to claim 1, wherein: The operating frequency of the transmission mechanism is 3900 bpm, the number of the air holes is 1, and the diameter of the air holes is 0.5 mm; or, The number of the air holes is two, the operating frequency of the transmission mechanism is 3650 bpm, and the diameter of the air holes is 1 mm.

7. The electric tool according to claim 1, wherein: The diameter of the air hole is negatively correlated with the frequency of the transmission mechanism.

8. The electric tool according to claim 1, wherein: The diameter of the pores ranges from 0.3 mm to 1.5 mm. Suppose the total flow area of ​​the pores is S mm 2 , the operating frequency of the transmission mechanism is F bpm, and the ratio of the total flow area S of the pores to the operating frequency F is in the range of 0.5*e -4 ~5*e -4 .

9. The electric tool according to claim 1, wherein: An internal thread is arranged on the inner wall of the oil filling hole, the oil cover includes an external thread connected to the oil filling hole, and the oil cover also includes a flange radially extending to the radial outside of the external thread, the flange presses the upper step surface of the oil filling hole and a sealing ring is arranged between the flange and the lower step surface of the oil filling hole.

10. The electric tool according to claim 1, wherein: The electric tool is a hammer and pick type electric tool.

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