Sealing device and use method for water pressure test of diesel engine front end box

Abstract

The present invention discloses a sealing device for a water pressure test of a front-end box of a diesel engine and a method for using the sealing device, which includes a tension sleeve, a pair of frustum-shaped tension nuts and a double-headed adjusting screw. The two ends of the tension sleeve formed by two semi-cylinder pairs are respectively provided with frustum-shaped holes, and the threads at both ends of the double-headed adjusting screw and the internal threads of the pair of frustum-shaped tension nuts are all rotated in opposite directions. The frustum-shaped tension nuts are respectively screwed on the corresponding ends of the double-headed adjusting screw and are located in the frustum-shaped holes at both ends of the tension sleeve. The tension sleeve, a pair of frustum-shaped tension nuts and one end of the double-headed adjusting screw are inserted into the special-shaped cavity of the front-end box of the diesel engine. The method for using the sealing device includes 1) assembling the sealing device and installing it into the two ends of the tension sleeve, 2) installing the sealing device into the special-shaped cavity of the front-end box, and 3) rotating the double-headed adjusting screw so that the sealing device seals the special-shaped cavity. The rubber pad on the outer side of the tension sleeve of the present invention is squeezed to produce elastic deformation, thereby improving the sealing performance of the special-shaped cavity and solving the sealing problem of the curved surface of the special-shaped cavity.

Description

Technical Field

[0001] The invention relates to a water pressure test of a cavity channel of a case body, and in particular to a sealing device and a test method for a water pressure test of a cavity channel of a case body of a diesel engine, belonging to the technical field of case body pressure resistance test. Background Art

[0002] The front end box is an important component of a medium-speed marine diesel engine (speed ≤ 4000r / min). It is installed on the front side of the diesel engine frame, and its bottom is fixed on the common base of the diesel engine. The channel cavities such as fuel, lubricating oil and circulating cooling water of the medium-speed marine diesel engine are integrated in the front end box, and a connecting cavity between the channel cavities is also set. The front end box is a cast iron part, and its quality directly affects the overall performance and service life of the diesel engine. In order to ensure the normal operation of the diesel engine, each channel cavity in the front end box must be able to transport fuel, lubricating oil and circulating cooling water respectively. The channel cavities that transport different fluid media cannot be connected, otherwise it will seriously affect the normal operation of the diesel engine and even cause safety accidents. In order to ensure the closure of each channel cavity in the front end box, each channel cavity of the front end box must be subjected to a water pressure test to check the sealing of the channel cavity. Each inlet and outlet of each channel cavity in the water pressure test must be sealed with a sealing device. A water inlet is installed on one of the sealing devices. Water is added to increase the pressure to the set value and then the pressure is maintained for a period of time. If the water pressure in the tested channel cavity does not drop significantly at this time, the channel cavity passes the water pressure test.

[0003] There is also a special-shaped cavity in the front box that connects the three channel cavities. The curved surface of the special-shaped cavity is difficult to seal, and it is necessary to develop a special sealing device to solve this problem. Summary of the invention

[0004] The purpose of the present invention is to provide a sealing device for a diesel engine front end box water pressure test which has a simple structure and can effectively seal a special-shaped cavity in the front end box and a method for using the sealing device.

[0005] The present invention is achieved through the following technical solutions:

[0006] A sealing device for a front-end box water pressure test of a diesel engine comprises two semi-cylindrical tension sleeves, a pair of frustum-shaped tension nuts and a double-ended adjusting screw, rubber pads are respectively bonded to the semi-cylindrical outer circumferences of the tension sleeves, the two semi-cylindrical tension sleeves are combined to form a cylinder with a gap in the middle, frustum-shaped holes are respectively provided at both ends of the cylinder, the small ends of the frustum-shaped holes are connected, and the circumference of the frustum-shaped holes matches the circumferential surface of the frustum-shaped tension nut; double-ended adjusting screw The threads at both ends of the adjusting screw are rotated in opposite directions, and the internal threads of a pair of frustum-shaped tensioning nuts are also rotated in opposite directions; the frustum-shaped tensioning nuts are respectively screwed on the corresponding ends of the double-headed adjusting screw, and the frustum-shaped outer peripheral surfaces of the frustum-shaped tensioning nuts are respectively embedded in the frustum-shaped holes at both ends of the cylindrical body formed by two semi-cylindrical tensioning sleeves, and the two semi-cylindrical tensioning sleeves, a pair of frustum-shaped tensioning nuts and one end of the double-headed adjusting screw are inserted into the special-shaped cavity of the front end box of the diesel engine.

[0007] The purpose of the present invention can also be further achieved by the following technical measures:

[0008] Furthermore, the ratio of the length L1 of the frustum-shaped tensioning nut to the length L of the frustum-shaped hole of the tensioning sleeve is: L1 / L=0.60-0.64. The taper of the frustum-shaped tensioning nut and the taper of the frustum-shaped hole of the tensioning sleeve are both 1:4.

[0009] Furthermore, the thickness of the rubber pad is 2.5-3.5 mm.

[0010] Furthermore, a polished rod section extends from the other end of the double-headed adjusting screw, the diameter of the polished rod section is smaller than the diameter of one end of the double-headed adjusting screw, and the end of the polished rod section is a cube.

[0011] Furthermore, the gap B between adjacent surfaces of the two semi-cylindrical tension sleeves is 3-5 mm.

[0012] A method for using a sealing device for a diesel engine front end box water pressure test comprises the following steps:

[0013] 1) Screw a pair of frustum-shaped tension nuts with opposite thread directions onto the corresponding ends of the double-ended adjusting screw until the distance B between the small end face of the frustum-shaped tension nut and the corresponding thread root is B = 4-5 mm;

[0014] 2) The cone holes of the two semi-cylindrical expansion sleeves with rubber pads bonded thereto are radially pressed against the outer circumferential surfaces of the cone-shaped expansion nuts, so that the cone-shaped expansion nuts are respectively embedded in the cone holes corresponding to the two ends of the expansion sleeves;

[0015] 3) Put the wrench on the cube at the other end of the double-ended adjusting screw, turn the wrench clockwise to drive the double-ended adjusting screw to rotate clockwise, thereby driving a pair of frustum-shaped tensioning nuts to move relatively close to each other, and the outer diameter of the tensioning sleeve increases until the outer diameter of the rubber pad of the tensioning sleeve is 0.3mm to 0.5mm smaller than the inner diameter of the special-shaped cavity to be sealed, and then insert the tensioning sleeve, a pair of frustum-shaped tensioning nuts and one end of the double-ended adjusting screw into the special-shaped cavity of the front end box of the diesel engine; continue to turn the wrench clockwise until the wrench cannot be turned, so that the two frustum-shaped tensioning nuts are close to each other, thereby increasing the outer diameter of the tensioning sleeve; the rubber pad on the outside of the tensioning sleeve is squeezed by the hole wall of the special-shaped cavity to produce elastic deformation, thereby completing the sealing of the special-shaped cavity;

[0016] 4) After the water pressure test is completed, turn the wrench counterclockwise to move the two conical tension nuts away from each other, thereby reducing the outer diameter of the tension sleeve and breaking the contact between the rubber pad and the hole wall of the special-shaped cavity. Then, the tension sleeve, a pair of conical tension nuts and the double-headed adjusting screw can be taken out.

[0017] The invention has a simple structure and is easy to use. It adopts a structure in which the frustum-shaped tightening nuts are respectively screwed on the two ends of the double-headed screw, and the frustum-shaped tightening nuts are respectively inserted into the frustum-shaped holes at the two ends of the tightening sleeve. The double-headed screw is rotated clockwise, and the frustum-shaped tightening nuts are relatively moved toward the length center direction of the tightening sleeve, thereby pushing the two semi-cylindrical tightening sleeves to move radially outward, so that the rubber pad outside the tightening sleeve in the special-shaped cavity is squeezed to produce elastic deformation, thereby improving the sealing performance of the special-shaped cavity. The invention solves the sealing problem of the curved surface of the special-shaped cavity by the structure in which the outer diameter of the tightening sleeve can be changed.

[0018] Advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments thereof, which are given by way of example only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the present invention;

[0020] Figure 2 yes Figure 1 Right view of . DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0022] like Figure 1 and Figure 2As shown, this embodiment includes two semi-cylindrical tension sleeves 1, a pair of frustum-shaped tension nuts 2 and a double-headed adjustment screw 3. Rubber pads 4 are respectively bonded to the semi-cylindrical outer circumference of the tension sleeve 1. The two semi-cylindrical tension sleeves 1 are paired to form a cylinder with a gap A=4mm in the middle. The two ends of the cylinder are respectively provided with frustum-shaped holes 11 with small ends connected. The circumference of the frustum-shaped hole 11 matches the frustum-shaped outer circumference of the frustum-shaped tension nut 2. The threads at the two ends of the double-headed adjustment screw 3 are rotated in opposite directions, and the internal threads of the pair of frustum-shaped tension nuts 2 are also rotated in opposite directions. The frustum-shaped tensioning nuts 2 are screwed onto the corresponding ends of the double-headed adjusting screw 3 respectively, and the frustum-shaped outer peripheral surfaces of the frustum-shaped tensioning nuts 2 are respectively embedded in the frustum-shaped holes 11 at both ends of the synthetic cylinder formed by two semi-cylindrical tensioning sleeves 1, and the two semi-cylindrical tensioning sleeves 1, a pair of frustum-shaped tensioning nuts 2 and the left end of the double-headed adjusting screw 3 are inserted into the special-shaped cavity 10 of the front end box of the diesel engine.

[0023] The ratio of the length L1 of the frustum-shaped tensioning nut to the length L of the frustum-shaped hole of the tensioning sleeve is: L1 / L=0.60~0.64, so that the frustum-shaped tensioning nut 2 has sufficient moving length in the frustum-shaped hole 11 of the tensioning sleeve 1, which expands the change in the outer diameter of the tensioning sleeve 1 and improves the application scope of the present invention. The taper of the frustum-shaped tensioning nut 2 of this embodiment and the taper of the frustum-shaped hole 11 of the tensioning sleeve 1 are both 1:4. The thickness of the rubber pad 4 is 3.0mm. A smooth rod section 31 extends from the right end of the double-headed adjustment screw 3. The diameter of the smooth rod section 31 is smaller than the diameter of the double-headed adjustment screw 3. The end of the smooth rod section 31 is a cube 311 that is easy to turn with a wrench.

[0024] A method for using a sealing device for a diesel engine front end box water pressure test comprises the following steps:

[0025] 1) Screw a pair of frustum-shaped tension nuts 2 with opposite threads onto the corresponding two ends of the double-headed adjusting screw 3 respectively, until the distance B between the small end face of the frustum-shaped tension nut 2 and the corresponding thread root is B=5mm, leaving a movable adjustment amount for the frustum-shaped tension nut 2.

[0026] 2) The two semi-cylindrical tension sleeves 1 with rubber pads 4 bonded thereto are radially pressed against the outer circumferential surfaces of the frustum-shaped tension nuts 2, so that the frustum-shaped tension nuts 2 are respectively embedded in the corresponding frustum-shaped holes 11 at both ends of the tension sleeve 1.

[0027] 3) Put the wrench on the square body 311 at the right end of the double-ended adjusting screw 3, turn the wrench clockwise, drive the double-ended adjusting screw 3 to rotate clockwise, thereby driving the pair of frustum-shaped tensioning nuts 2 to move relatively close, and the outer diameter of the tension sleeve 1 increases until the outer diameter of the rubber pad 4 of the tension sleeve 1 is 0.3mm~0.5mm smaller than the inner diameter of the special-shaped cavity 10 to be sealed, and then insert the tension sleeve 1, the pair of frustum-shaped tensioning nuts 2 and the left end of the double-ended adjusting screw 3 into the special-shaped cavity 10 of the front end box of the diesel engine. Continue to turn the wrench clockwise until the wrench cannot be turned, so that the two frustum-shaped tensioning nuts 2 are close to each other, thereby increasing the outer diameter of the tension sleeve 1. The rubber pad 4 on the outside of the tension sleeve 1 is squeezed by the hole wall of the special-shaped cavity 10 to produce elastic deformation, thereby completing the sealing of the special-shaped cavity 10.

[0028] 4) After the water pressure test is completed, turn the wrench counterclockwise to move the two conical tension nuts 2 away from each other, thereby reducing the outer diameter of the tension sleeve 1 and disengaging the rubber pad 4 from the hole wall of the special-shaped cavity 10. Then, the tension sleeve 1, a pair of conical tension nuts 2 and the double-headed adjusting screw 3 can be removed.

[0029] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A sealing device for a diesel engine front end box water pressure test, characterized in that: The invention comprises two semi-cylindrical tensioning sleeves, a pair of frustum-shaped tensioning nuts and a double-ended adjusting screw, rubber pads are respectively bonded on the semi-cylindrical outer circumferential surfaces of the tensioning sleeves, the two semi-cylindrical tensioning sleeves are combined to form a cylinder with a gap in the middle, frustum-shaped holes are respectively provided at both ends of the cylinder, the small ends of the frustum-shaped holes are communicated, and the circumferential surfaces of the frustum-shaped holes match the frustum-shaped outer circumferential surfaces of the frustum-shaped tensioning nuts; the threads at both ends of the double-ended adjusting screws are rotated in opposite directions, and the internal threads of the pair of frustum-shaped tensioning nuts are also rotated in opposite directions; the frustum-shaped tensioning nuts are respectively screwed on the corresponding ends of the double-ended adjusting screws, and the frustum-shaped outer circumferential surfaces of the frustum-shaped tensioning nuts are respectively embedded in the frustum-shaped holes at both ends of the cylinder formed by the two semi-cylindrical tensioning sleeves, and the two matched semi-cylindrical tensioning sleeves, a pair of frustum-shaped tensioning nuts and one end of the double-ended adjusting screw are inserted into the special-shaped cavity of the front end box of the diesel engine; The ratio of the length L1 of the frustum-shaped tensioning nut to the length L of the frustum-shaped hole of the tensioning sleeve is: L1 / L=0.60~0.64; The taper of the frustum-shaped tensioning nut and the taper of the frustum-shaped hole of the tensioning sleeve are both 1:

4.

2. The sealing device for the water pressure test of the front end box of a diesel engine as claimed in claim 1, characterized in that: The thickness of the rubber pad is 2.5-3.5 mm.

3. The sealing device for the water pressure test of the front end box of a diesel engine as claimed in claim 1, characterized in that: A polished rod section extends from the other end of the double-headed adjusting screw rod. The diameter of the polished rod section is smaller than the diameter of the double-headed adjusting screw rod. The end of the polished rod section is a cube.

4. The sealing device for the water pressure test of the front end box of a diesel engine as claimed in claim 1, characterized in that: The gap A between the adjacent surfaces of the two semi-cylindrical tension sleeves is 3 to 5 mm.

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