A method for pre-drilling foot bolt holes for a four-cylinder fork-type steering gear

Abstract

The present invention discloses a method for pre-drilling the bolt holes of the bottom foot of a four-cylinder slewing fork steering gear. The method uses a straight edge to mark the front and rear ends of the tiller. AB 、l CD Mark four points, A, B, C, and D, where the straightedge meets both sides of the tiller groove. These four points, along with the cylinder centerline points I, J, K, and M, serve as reference points. By marking the positions of the bottom corner bolt holes without pre-installing the servo, the work of assembling, calibrating, and dismantling the servo to locate the bolt holes is reduced, thus avoiding duplication of work, reducing the workload, and shortening the installation cycle.

Description

Technical Field

[0001] The invention relates to the technical field of ship steering gear installation, and in particular to a method for drilling a foot bolt hole of a slewing fork type steering gear. Background Art

[0002] During the shipbuilding process, the steering gear is a heading control device that enables operations such as steering, turning, and sailing straight, and is an important equipment for ship navigation. There are rotary vane steering gears, yoke steering gears, etc. The most common one is the four-cylinder yoke steering gear, which mainly includes a tiller and four cylinders. The plungers of the four cylinders are assembled together with the tiller, and the tiller and the four steering gears are all installed on the base. The installation method of the yoke steering gear in the prior art is disclosed in the Chinese patent application number CN201910015298.6 (publication number CN109866872A) "A method for assembling a steering gear." The installation method includes the following steps: installing the tiller of the servo motor onto the base; installing the four oil cylinders of the servo motor onto the base, and assembling the four oil cylinders and the tiller together; adjusting the relative positions of the four oil cylinders and the tiller in the horizontal direction, so that the difference in the distance between the reference points of the four oil cylinders and the axis of the tiller is not greater than the set distance; adjusting the relative positions of the four oil cylinders and the tiller in the vertical and horizontal directions, so that the difference in the distance between the axis of the four oil cylinders and the reference plane of the tiller is not greater than the set height; fixing the relative positions of the oil cylinders and the tiller in the vertical and horizontal directions.

[0003] According to the aforementioned servo installation method, ensuring the servo's operational accuracy requires ensuring its precise positioning and installation. However, because the servo's positioning is affected by the relative positions of the rudder stock and rudder blades, and the rudder stock and tiller, the servo must be pre-installed by continuous adjustment according to technical requirements. The servo is then removed using a special punch to mark the bolt installation holes. After drilling holes in the marked locations, the servo is then repositioned and installed. Consequently, installing a scotch fork motor using existing technology presents significant challenges, including a large engineering workload, a long installation cycle, and repeated work.

[0004] Therefore, further improvements need to be made to the existing technology. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for pre-drilling base bolt holes without pre-installing a steering gear.

[0006] The technical solution adopted by the present invention to solve the above technical problems is: a method for pre-drilling the foot bolt holes of a four-cylinder slewing fork steering gear, comprising:

[0007] Step 1: Rotate the rudder blade to zero position: Hang a line weight on the left and right center of the rudder blade to make the left and right center lines of the rudder blade coincide with the center line of the hull on the slipway;

[0008] Step 2, determine the base point and baseline: Place the first straight ruler along the two front prongs of the tiller fork on the base plane, mark two base points at the contact point between the first straight ruler and the inner side of the tiller groove, record them as A and B, place the first straight ruler along the two rear prongs of the tiller fork, mark two base points at the contact point between the first straight ruler and the inner side of the tiller groove, record them as C and D, and draw a straight line through the base points A and B. AB and the straight line l passing through the base points C and D CD As a baseline, the baseline l AB With l CD They are all perpendicular to the left and right center lines of the tiller;

[0009] Step 3: Draw the line connecting the inner bolt holes: Starting from the base point and taking the left and right center lines of the tiller as the center, select points at a distance L1 outward along the base line, denoted as E, F, G, and H, where L1 is the distance from the inner side of the tiller fork to the first bolt hole. Draw a straight line lEF passing through points E and F and a straight line l passing through points G and H. GH The inner bolt hole connection line of the oil cylinder, 1 EF and l GH Parallel to the left and right center lines of the tiller;

[0010] Step 4: Draw the centerline of the oil cylinder: There are known points I, J, K, and M on the tiller fork, which are the centerline points of the oil cylinder. Use a second ruler to draw a straight line l passing through points I and J. IJ and the straight line l passing through points K and M KM As the center line of the oil cylinder, keep the hull level and use the plumb line to lead it to the base plane to obtain the straight line l IJ With l KM The projection and l EF 、l GH The intersection points are marked as O, P, Q, and R respectively;

[0011] Step 5: Draw the line connecting the outer bolt holes: Draw a straight line l passing through points O and P oP and the straight line l passing through points Q and R QR , starting from points O, P, Q, and R, with the left and right center lines of the tiller as the center, follow the straight line l OP 、l QR Intercept the points S, T, U, and V at a distance of L3, where L3 is the distance from the first bolt hole to the last bolt hole of a single cylinder, and draw a straight line l passing through points S and T. ST and the straight line l passing through points U and V UV As the outer bolt hole connection line, l ST With l UV They are parallel to the left and right center lines of the tiller;

[0012] Step 6, determine all inner and outer bolt hole points: starting from point O, P, Q, P, S, T, U, V, along the straight line lEF 、l ST 、l GH 、l UV The points at a distance of L4 at both ends are taken as the inner and outer bolt hole points, and are recorded as a, b, c, d, e, f, g, h, i, j, k, m, n, o, p, q, where L4 is the distance from the center line of the cylinder to the bolt hole.

[0013] Step 7, determine the remaining bolt hole points: connect the end points to draw line segments ae, bf, cg, dh, io, jp, kq, and mr. If the inner and outer bolt hole points are known, mark the points of the remaining bolt holes on the drawn line segments according to the drawings;

[0014] Step 8, Drilling: Use a magnetic drill equipped with the corresponding core drill bit to drill holes according to the marked bolt hole points.

[0015] As an improved solution of the present invention, L1 in step 3 is obtained by calculation, and the calculation formula is: L1=Ld / 2, where L1 is the distance from the inner side of the tiller fork to the first bolt hole; L is the distance from the center of the tiller fork to the first bolt hole; d is the width of the tiller fork groove.

[0016] As an improved solution of the present invention, in step 4, when the ship is tilted, a plumb line is used to lead the straight line l on the steering engine base. EF 、l GH On the straight line l IJ With l KM The projection and lEF, l GH After the intersection of the line and the steering gear, the points obtained after moving L5 in the direction of the slipway height are recorded as O, P, Q, and R, where L5 = HA, H is the distance between the marked plane and the steering gear base, and A is the slope ratio of the slipway before and after when the ship is built.

[0017] As an improvement to the present invention, step 5 also includes checking the accuracy of marking, connecting points S and Q, T and O, R and U, P and V to make line segments r1, r2, r3, and r4, respectively, and checking whether the lengths of line segments r1, r2, r3, and r4 are equal, and the error is within 1 mm. If the error is out of tolerance, the marking work needs to be checked and re-marked.

[0018] As an improved solution of the present invention, step 8 further includes marking out a cutting circle and a test circle for each bolt hole to calibrate the position of the core drill bit and check whether the drilling position is correct.

[0019] Compared with the existing technology, the present invention has the following advantages: by determining the base point and baseline and coordinating them with the centerline of the oil cylinder, the present invention can accurately locate the locations of all bottom corner bolt holes and complete drilling without pre-installing the steering gear by comparing them with the drawing data. This improves the previous pre-drilling method to marking and pre-drilling, reducing the work of assembling, calibrating, and removing the steering gear to locate the bolt holes, avoiding duplication of work, reducing the amount of work, and shortening the installation cycle. Specifically, it reduces the labor cost by approximately 20 and shortens the production cycle by approximately 5 days, greatly improving installation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a top view of an embodiment of the present invention in an unlined state;

[0021] Figure 2 Schematic diagram of the positions of the first straightedge and the second straightedge according to an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of step 2 of an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of step 3 of an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of step 4 of an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of step 5 of an embodiment of the present invention;

[0026] Figure 7 This is a schematic diagram of steps 6 to 7 of an embodiment of the present invention; DETAILED DESCRIPTION

[0027] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0028] like Figures 1 to 7 Shown are preferred embodiments of the present invention.

[0029] A method for pre-drilling foot bolt holes of a four-cylinder scotch fork steering gear comprises:

[0030] Step 1: Rotate the rudder blade to zero position: Hang a line weight on the left and right center of the rudder blade to make the left and right center lines of the rudder blade coincide with the center line of the hull on the slipway;

[0031] Step 2: Determine the base point and baseline: Figure 3As shown, on the plane of the base 1, place the first straight ruler 4 along the two front prongs of the tiller 2 fork, mark two base points at the contact point between the first straight ruler 4 and the inner side of the tiller 2 groove, record them as A and B, place the first straight ruler 4 along the two rear prongs of the tiller 2 fork, mark two base points at the contact point between the first straight ruler 4 and the inner side of the tiller 2 groove, record them as C and D, and draw a straight line l passing through the base points A and B. AB and the straight line l passing through the base points C and D CD As a baseline, the baseline l AB With l CD They are all perpendicular to the left and right center lines of the tiller 2;

[0032] Step 3: Draw the lines connecting the inner bolt holes: Figure 4 As shown, starting from the base point and taking the left and right center lines of the tiller 2 as the center, take points at a distance L1 outward along the base line, and record them as E, F, G, and H, where L1 is the distance from the inner side of the fork of the tiller 2 to the first bolt hole, and draw a straight line l passing through points E and F. EF and the straight line l passing through points G and H GH is the line connecting the inner bolt holes of the oil cylinder, l EF and l GH Parallel to the left and right center lines of tiller handle 2;

[0033] Step 4: Draw the center line of the cylinder: Figure 5 As shown, there are known points I, J, K, and M on the tiller 2 fork, which is the center line point 3 of the oil cylinder. Use the second ruler (5) to draw a straight line l passing through points I and J. IJ and the straight line l passing through points K and M KM As the center line of the oil cylinder, keep the hull level and use the plumb line to lead it to the plane of the base 1 to obtain the straight line l IJ With l KM The projection and l EF 、l GH The intersection points are marked as O, P, Q, and R respectively;

[0034] Step 5: Draw the lines connecting the outer bolt holes: Figure 6 As shown, draw a straight line l passing through points O and P oP and the straight line l passing through points Q and R QR , starting from points O, P, Q, and R, and centering on the left and right center lines of the tiller 2, along the straight line l oP 、l QR Intercept the points S, T, U, and V at a distance of L3, where L3 is the distance from the first bolt hole to the last bolt hole of a single cylinder. Draw a straight line lsT passing through points s and T and a straight line l passing through points U and V. Uv As the outer bolt hole connection line, l ST With l UV They are all parallel to the left and right center lines of the tiller 2;

[0035] Step 6: Determine all inner and outer bolt hole points: Figure 7 As shown, starting from point O, P, Q, P, S, T, U, V, along the straight line l EF 、l ST 、l GH 、l UV The points at a distance of L4 at both ends are taken as the inner and outer bolt hole points, and are recorded as a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, and p, where L4 is the distance from the center line of the cylinder to the bolt hole.

[0036] Step 7, determine the remaining bolt hole points: connect the end points to draw line segments ae, bf, cg, dh, io, jp, kq, and mr. If the inner and outer bolt hole points are known, mark the points of the remaining bolt holes on the drawn line segments according to the drawings;

[0037] Step 8, Drilling: Use a magnetic drill equipped with the corresponding core drill bit to drill holes according to the marked bolt hole points.

[0038] To ensure accurate marking, as described in step 1, the rudder blade must be placed at zero position before marking.

[0039] In order to ensure that the straight line l EF 、l GH As described in step 2, use the first straight ruler 4 to draw a straight line l at the front and rear ends of the tiller 2. AB 、l CD Mark four points A, B, C, and D where the first straight ruler 4 contacts both sides of the tiller 2 slot; all distances from the tiller 2 are measured based on these four points.

[0040] Since the centerline of the tiller 2 is a virtual line and cannot be used in actual measurement, the measurement must be based on the side of the tiller 2 where the groove is removed. This requires a size conversion of L1 described in step 3. L1 in step 3 is calculated using the following formula: L1 = Ld / 2, where L1 is the distance from the inside of the tiller 2 fork to the first bolt hole; L is the distance from the center of the tiller 2 fork to the first bolt hole; and d is the width of the tiller 2 fork slot.

[0041] In order to ensure the accuracy of the measurement data, as described in step 4, take A, B, C, and D as the reference and follow the straight lines lAB, l CD Measure L1, take points E, F, G, H, and connect EF and GH. The first bolt hole of the servo seat is located at l EF 、l GH superior.

[0042] Since the front and rear center line of the tiller 2 is a virtual line, it is impossible to accurately find the line that passes through the center of the tiller 2 and is perpendicular to the left and right center lines of the tiller 2 during actual operation. As described in step 4, use the cylinder center line point 3 given by the manufacturer on the tiller 2 as the reference, and use a plumb line to draw a line l on the servo base 1. EF 、l GH If the ship is built horizontally, this point is the desired point. If it is built at an angle, move it forward by L5, which is the desired point. Specifically, L5 = HA, where H is the distance from the marked plane to the steering gear base 1, and A is the slope ratio of the slipway to the fore and aft during ship construction.

[0043] Step 5 also includes checking the accuracy of marking. Connect points S and Q, T and O, R and U, P and V to make line segments r1, r2, r3, and r4 respectively. Check whether the lengths of line segments r1, r2, r3, and r4 are equal. The error is within 1mm. If it exceeds the tolerance, the marking work needs to be checked and re-marked.

[0044] Step 7 is the location of the four bolt holes for each cylinder.

[0045] Step 8 also includes marking a cutting circle and a test circle, which are used to calibrate the position of the core drill bit and to check whether the drilling position is correct.

[0046] The present invention improves the previous pre-drilling method to pre-drilling with marking, which reduces the work of assembling, calibrating and dismantling the steering gear to find the location of the bolt holes, reduces the manpower by about 20 and shortens the production cycle by about 5 days.

Claims

1. A method for pre-drilling foot bolt holes for a four-cylinder scotch fork servo, comprising: Step 1: Rotate the rudder blade to zero position: Hang a line weight on the left and right center of the rudder blade to make the left and right center lines of the rudder blade coincide with the center line of the hull on the slipway; Step 2, determine the base point and baseline: Place the first straight ruler (4) along the two front prongs of the tiller (2) fork on the plane of the base (1), mark two base points at the contact point between the first straight ruler (4) and the inner side of the tiller (2) groove, record them as A and B, place the first straight ruler (4) along the two rear prongs of the tiller (2) fork, mark two base points at the contact point between the first straight ruler (4) and the inner side of the tiller (2) groove, record them as C and D, and draw a straight line through the base points A and B. AB and the straight line l passing through the base points C and D CD As a baseline, the baseline l AB With l CD They are all perpendicular to the left and right center lines of the tiller (2); Step 3, draw the line connecting the inner bolt holes: starting from the base point and taking the left and right center lines of the tiller (2) as the center, take points at a distance L1 outward along the base line, record them as E, F, G, H, where L1 is the distance from the inner side of the tiller (2) fork to the first bolt hole, and draw a straight line l passing through points E and F. EF and the straight line l passing through points G and H GH is the line connecting the inner bolt holes of the oil cylinder, l EF and l GH Parallel to the left and right center lines of the tiller (2); Step 4: Draw the center line of the oil cylinder: There are known points I, J, K, and M on the tiller (2) shift fork as the center line point of the oil cylinder (3). Use the second ruler (5) to draw a straight line l passing through points I and J. IJ and the straight line l passing through points K and M KM As the center line of the oil cylinder, keep the hull level and use a plumb line to draw it to the plane of the base (1), and get a straight line l IJ With l KM The projection and l EF 、l GH The intersection points are marked as O, P, Q, and R respectively; Step 5: Draw the line connecting the outer bolt holes: Draw a straight line l passing through points O and P OP and the straight line l passing through points Q and R QR , starting from points O, P, Q, and R, and with the left and right center lines of the tiller (2) as the center, follow the straight line l OP 、l QR Intercept the points S, T, U, and V at a distance of L3, where L3 is the distance from the first bolt hole to the last bolt hole of a single cylinder, and draw a straight line l passing through points S and T. ST and the straight line l passing through points U and V UV As the outer bolt hole connection line, l ST With l UV They are parallel to the left and right center lines of the tiller (2); Step 6, determine all inner and outer bolt hole points: starting from point O, P, Q, R, S, T, U, V, along the straight line l EF 、l ST 、l GH 、l UV The points at the distance L4 at both ends are taken as the inner and outer bolt hole points, which are recorded as a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, and p, where L4 is the distance from the center line of the cylinder to the bolt hole; Step 7, determine the remaining bolt hole points: connect the end points to draw line segments ae, bf, cg, dh, io, jp, kq, and mr. If the inner and outer bolt hole points are known, mark the points of the remaining bolt holes on the drawn line segments according to the drawings; Step 8, Drilling: Use a magnetic drill equipped with the corresponding core drill bit to drill holes according to the marked bolt hole points.

2. The pre-drilling method for the foot bolt holes of a four-cylinder scotch fork steering gear according to claim 1, characterized in that: In step 3, L1 is obtained by calculation using the following formula: L1=Ld / 2, wherein L1 is the distance from the inner side of the tiller (2) fork to the first bolt hole; L is the distance from the center of the tiller (2) fork to the first bolt hole; and d is the width of the tiller (2) fork slot.

3. The method for pre-drilling foot bolt holes of a four-cylinder scotch fork steering gear according to claim 2, characterized in that: In step 4, when the ship is tilted, use a plumb bob to draw a straight line l on the steering engine base (1). EF 、l GH On the straight line l IJ With l KM The projection and l EF 、l GH After the intersection of the two points, the points obtained after moving a distance L5 in the direction of the slipway height are recorded as O, P, Q, and R, where L5 = HA, H is the distance between the marked plane and the steering gear base (1), and A is the slope ratio of the slipway before and after the ship is built.

4. The method for pre-drilling foot bolt holes of a four-cylinder scotch yoke steering gear according to claim 3, characterized in that: The step 5 also includes checking the accuracy of marking, connecting points S and Q, T and O, R and U, P and V to make line segments r1, r2, r3, and r4 respectively, and checking whether the lengths of line segments r1, r2, r3, and r4 are equal. The error is within 1mm. If it exceeds the tolerance, the marking work needs to be checked and re-marked.

5. The method for pre-drilling foot bolt holes of a four-cylinder scotch yoke steering gear according to any one of claims 1 to 4, characterized in that: The step 8 also includes marking out a cutting circle and a test circle for each bolt hole to calibrate the position of the core drill bit and check whether the drilling position is correct.

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