Method and apparatus for tapping engine components for orientation of spark plugs

Abstract

The present disclosure provides "Methods and apparatus for tapping an engine component for spark plug orientation". A method and apparatus for tapping an engine component for spark plug orientation, comprising: measuring tap pitch; measuring a first distance; calculating a hypothetical first tap tooth based on the pitch and the first distance; determining a tap rotation offset; calculating a tap rotation start orientation, the tap rotation start orientation being the first location minus the tap rotation offset minus a spark plug offset; rotating a tool head to the rotation start orientation; positioning the tap; synchronizing a rotation speed of the tool head and a feed rate to the tap thread pitch; and operating the tool to cut or form threads in the engine component.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for tapping engine components to orient spark plugs. Background Technology

[0002] The statements in this section provide only background information in relation to this disclosure and may not constitute prior art.

[0003] Spark plugs for internal combustion engines typically include a ground strip spaced apart from the center electrode to form a spark plug gap. A controlled arc discharge across the gap typically provides an ignition spark to ignite the compressed air-fuel mixture in the combustion chamber. The ground strip is typically attached to one side of the spark plug body. The orientation of the ground strip relative to the engine's intake and exhaust valves can alter engine performance (e.g., fuel economy) by changing the flow patterns of the air-fuel mixture and combustion gases in the combustion chamber.

[0004] Consistently orienting the grounding strip at a predetermined and desired rotational position relative to the valve can improve the consistency of performance between different engines during production. The orientation of the grounding strip typically depends on the characteristics of the internal threads of the engine cylinder head and the external threads of the spark plugs. However, standard thread tapping machines use tapered taps, which cannot predictably orient the internal threads of the engine cylinder head. To address this limitation, some engine cylinder heads have threads formed by a thread milling operation, which involves a milling drill bit with a single cutting face that rotates helically around the inner diameter of the hole to form the thread. However, thread milling can be a slow and expensive process compared to standard thread tapping, and is prone to tool wear or breakage due to the horizontal forces on the helically moving drill bit. Attempting to use a standard thread tapping drill bit typically involves some trial and error process, such as forming a first test part and then adjusting the settings so that subsequent parts are correctly oriented. However, this trial-and-error approach is slow and results in part waste and additional tool wear.

[0005] The threading device and method disclosed herein overcome these limitations of typical spark plug tapping processes and can provide correctly oriented spark plugs in the first part while using durable and fast standard thread taps. Summary of the Invention

[0006] In one form, a method of tapping an engine component to orient a spark plug in the combustion chamber of an internal combustion engine includes mounting a tap to a tool head and measuring the thread pitch of the tap. The method includes measuring a first distance between the end face of the tap and the center of a predetermined full tooth of the tap, the first distance being measured at a first rotational position of the tap. The method includes calculating an imaginary first tooth of the tap based on the thread pitch and the first distance. The method includes determining a tap rotational offset from the first rotational position to a rotational position where the end face of the tap intersects the imaginary first tooth of the tap at the large diameter of the imaginary first tooth. The method includes determining a spark plug offset. The method includes calculating a tap rotational initial orientation, the tap rotational initial orientation being equal to the first rotational position minus the tap rotational offset minus the spark plug offset. The method includes rotating the tool head to the rotational initial orientation. The method includes positioning the tap such that the end face of the tap is a pitch increment distance of the tap away from the engine component. The method includes synchronizing the rotational speed of the tool head and the feed rate of the engine component relative to the tool head to the thread pitch of the tap and operating the tool to cut or form threads in the engine component.

[0007] According to another form, the method further includes calculating a mathematical configuration of teeth extending from the predetermined full teeth of the tap to the end surface of the tap based on the thread pitch of the tap and the first distance, the mathematical configuration of the teeth including the hypothetical first tooth.

[0008] According to another approach, determining the spark plug offset includes measuring the parameters of the spark plug and calculating the spark plug offset based on the parameters of the spark plug.

[0009] According to another embodiment, determining the spark plug offset includes: measuring the thread pitch of the spark plug; measuring a second distance between the end surface of the spark plug and the center of a predetermined tooth of the spark plug, the second distance being measured at a second rotational position of the spark plug; measuring a third distance between the end surface of the spark plug and the seat of the spark plug; calculating an imaginary first tooth of the spark plug based on the thread pitch of the spark plug and the second distance; and calculating the spark plug offset based on the imaginary first tooth of the spark plug, the third distance, and the second rotational position.

[0010] According to another form, the tap has threads that are chamfered toward the end surface of the tap.

[0011] According to another embodiment, the tap includes a plurality of partial threads near the end surface of the tap.

[0012] In another embodiment, a laser tool is used to set a gauge or a shadow gauge to measure the thread pitch of the tap and the first distance.

[0013] In another form, a method of tapping an engine component to orient a spark plug in the combustion chamber of an internal combustion engine includes mounting a tap to a tool head and measuring the thread pitch of the tap. The method includes measuring a first distance between the end face of the tap and the center of a predetermined tooth of the tap, the first distance being measured at a first rotational position of the tap. The method includes calculating a tap rotational overshoot equal to the first distance divided by the thread pitch of the tap. The method includes calculating a tap rotational offset equal to the tap rotational overshoot minus a maximum integer value of the tap rotational overshoot, multiplied by 360°. The method includes determining a spark plug offset. The method includes calculating a tap rotational initial orientation based on the first rotational position, the tap rotational offset, and the spark plug offset. The method includes rotating the tool head to the tap rotational initial orientation. The method includes positioning the tap such that the end face of the tap is a pitch increment distance away from the engine component. The method includes synchronizing the rotational speed of the tool head and the feed rate of the engine component relative to the tool head to the thread pitch of the tap and operating the tool to cut threads in the engine component.

[0014] According to another approach, determining the spark plug offset includes measuring the parameters of the spark plug and calculating the spark plug offset based on the parameters of the spark plug.

[0015] According to another embodiment, determining the spark plug offset includes: measuring the thread pitch of the spark plug; measuring a second distance between the end surface of the spark plug and the center of a predetermined tooth of the spark plug, the second distance being measured at a second rotational position of the spark plug; measuring a third rotational position, the third rotational position being the rotational offset from the second rotational position to the ground strip of the spark plug; measuring a third distance between the end surface of the spark plug and the seat of the spark plug; calculating spark plug rotational overshoot, the spark plug rotational overshoot being equal to the second distance divided by the thread pitch of the spark plug; and calculating spark plug rotational offset, the spark plug rotational offset being equal to the spark plug rotational overshoot minus the spark plug... The maximum integer value of the rotational overshoot is multiplied by 360°; the number of rotations for placing the spark plug is calculated, which is equal to the third distance divided by the thread pitch of the spark plug; the reference completion position of the spark plug is calculated, which is equal to the number of rotations for placing the spark plug minus the maximum integer value of the number of rotations for placing the spark plug, and then multiplied by 360°; the completed electrode offset is calculated, which is equal to the spark plug rotational offset plus the reference completion position of the spark plug; and the spark plug offset is calculated, which is equal to the third rotational offset minus the completed electrode offset minus the second rotational position.

[0016] According to another form, the third rotational offset is equal to 0°.

[0017] According to another form, the tap has threads that are chamfered toward the end surface of the tap.

[0018] According to another embodiment, the tap includes a plurality of partial threads near the end surface of the tap.

[0019] In another form, the predetermined tooth is a full tooth.

[0020] In another embodiment, a laser tool is used to set a gauge or a shadow gauge to measure the thread pitch of the tap and the first distance.

[0021] According to another form, the initial orientation of the tap rotation is equal to the adjustment factor plus the first rotation position minus the tap rotation offset minus the spark plug offset.

[0022] According to another form, the adjustment factor is a positive or negative integer multiple of 0° or 360°, which is configured such that the initial orientation of the tap rotation is within the range of 0° to 360°.

[0023] In another form, a threading device includes a tool, a tap, at least one sensor, and a control module. The tool includes a chuck configured to rotate about an axis. The tap is coupled to the chuck to rotate together about the axis. The at least one sensor is configured to detect the thread pitch of the tap and a first distance between the end face of the tap and the center of a predetermined full tooth of the tap. The first distance is measured at a first rotational position of the tap. The control module communicates with the at least one sensor and the tool. The control module is configured to calculate the position of an imaginary first tooth based on the thread pitch of the tap and the first distance. The end face intersects the imaginary first tooth at its large diameter. The control module is configured to calculate the initial rotational orientation of the tap based on the first rotational position, the position of the imaginary first tooth, and a spark plug offset. The control module communicates with the tool and is configured to synchronize the rotational speed of the chuck and the feed rate of the engine component relative to the chuck to the thread pitch of the tap, so as to cut or form threads in the engine component based on the initial orientation of the tap rotation.

[0024] In another embodiment, the control module is configured to control the axial position of the tap relative to the engine component based on an input representing the total length of the tap and the first rotational position.

[0025] Other areas of application will become apparent from the description provided herein. It should be understood that the descriptions and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0026] To facilitate a good understanding of this disclosure, various forms of the disclosure will now be described by way of example with reference to the accompanying drawings, in which:

[0027] Figure 1 It is a bottom plan view of a portion of the engine cylinder head and spark plug according to the teachings of this disclosure;

[0028] Figure 2 This is a side view of a thread tapping tool according to the teachings of this disclosure, showing the thread tapping tool and a portion of an engine cylinder head;

[0029] Figure 3 yes Figure 2 A side view of a thread tapping drill bit for a thread tapping tool;

[0030] Figure 4 yes Figure 3 A top view of a thread tapping drill bit, showing Figure 2 Sensors for thread tapping tools;

[0031] Figure 5 Yes Figure 2 A flowchart of the method for tapping cylinder heads;

[0032] Figure 6 yes Figure 3 A side profile view of a portion of a thread tapping drill bit, showing the calculated hypothetical first tooth;

[0033] Figure 7 This is a side view of a spark plug measuring tool according to the teachings of this disclosure, showing the chuck of the measuring tool that holds the spark plug;

[0034] Figure 8 yes Figure 7 A partial side profile of a spark plug, showing the calculated hypothetical first tooth;

[0035] Figure 9 yes Figure 7 A bottom view of the spark plug; and

[0036] Figure 10 It is determined in accordance with the teachings of this disclosure for use in Figure 5 The flowchart shows the spark plug rotation offset method used in the method.

[0037] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this disclosure in any way. Detailed Implementation

[0038] The following description is exemplary in nature only and is not intended to limit this disclosure, its application, or its uses. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features.

[0039] refer to Figure 1 This diagram illustrates a portion of an internal combustion engine. The engine includes a cylinder head 10, spark plugs 14, a pair of intake valves 18 and 22, and a pair of exhaust valves 26 and 30, which form the top of a combustion chamber 32. The intake valves 18 and 22 are adjacent to each other and disposed on one side of the combustion chamber 32, while the exhaust valves 26 and 30 are adjacent to each other and disposed on opposite sides of the combustion chamber 32. In the provided example, the cylinder head 10 includes a threaded hole 34 approximately at the center of the combustion chamber 32, and the spark plug 14 is screwed into the hole 34. The spark plug 14 includes a body 810, an electrode 814, and a spark plug 810. Figure 8(shown in the diagram) and grounding strip 818. The body 810 is threaded to be threadedly received in the hole 34. When the body 810 is screwed into the hole 34, the electrode 814 is positioned at the center of the body 810 and within the combustion chamber 32. The grounding strip 818 is attached to one side of the body 810 and extends radially inward to overlap with the electrode 814. The electrode 814 and the grounding strip 818 are spaced apart to define a spark gap within the combustion chamber 32.

[0040] In the provided example, the intake valves 18 and 22 are equally defined between them along the 0° axis, and the grounding strip 818 is shown oriented at 90° such that it is perpendicular to the 0° axis. It has been found that orienting the grounding strip 818 within the angular region indicated by reference numerals 110 or 114 (e.g., approximately 41° to 139° or 221° to 319°) produces improved flow dynamics within the combustion chamber 32 compared to other orientations, because the grounding strip 818 causes less interference with the intake and exhaust flow of gases in the combustion chamber 32.

[0041] refer to Figure 2 The thread tapping device 210 is shown as part of a cylinder head 214. The cylinder head 214 includes a hole similar to 34 ( Figure 1 The difference is that the internal thread is not yet formed in the hole 218 to receive the spark plug 14. Figure 1 In addition to the above, in the provided example, hole 218 is countersunk to define shoulder 222 on which spark plug 14 is mounted. The thread tapping device 210 includes a tool head or chuck 226, a thread tapping drill bit 230, a control module 234, and a sensor 238. Although a single sensor is shown and described herein, sensor 238 may include multiple sensors that operate independently or collaboratively to measure the characteristics described herein.

[0042] Chuck 226 is mounted to rotate about tool axis 242. Chuck 226 is configured to hold thread tap 230 such that thread tap 230 is coaxially positioned with tool axis 242 and rotates together with chuck 226 about tool axis 242. Sensor 238 is offset from tool axis 242 and spaced apart from thread tap 230. Sensor 238 communicates with control module 234, and control module 234 is configured to control the operation of sensor 238 and receive signals from sensor 238. Sensor 238 can be any suitable type of sensor configured to detect the orientation of thread tap 230 (e.g., a shaded profile gauge or laser gauge), and is described in more detail below.

[0043] Control module 234 is configured to control the rotational position of chuck 226 and the axial position of chuck 226 relative to the engine component (i.e., cylinder head 214). In the provided example, control module 234 is configured to align tool axis 242 coaxially with hole 218 and rotate thread tap 230 about tool axis 242, while simultaneously moving the thread tap 230 toward cylinder head 214 at a rate synchronized with the rotation of thread tap 230 and inserting it into hole 218 to form internal threads within hole 218. The threading process is described in more detail below. In an alternative configuration, the axial position of thread tap 230 may be stationary, while cylinder head 214 moves axially relative to rotating thread tap 230.

[0044] For further reference Figure 3 and Figure 4 The end portion 310 of the thread tapping drill 230 includes a plurality of cutting sections 314 circumferentially spaced around a tool axis 242. The cutting sections 314 extend axially a predetermined distance from the end face 318 of the thread tapping drill 230. Each cutting section 314 includes a plurality of teeth 322 configured to form an internal thread having a large diameter (i.e., at the peak 326 of the tooth 322) and a small diameter (i.e., at the valley 330 of the tooth 322). The cutting sections 314 are chamfered or tapered toward the end face 318 such that the teeth 322 near the end face 318 are not full teeth 322 (i.e., they have flat tops instead of peaks 326 and do not extend radially outwards to the entire large diameter 322). The teeth 322 are tapered such that the region of the cutting section 314 away from the end face 318 includes full teeth of the teeth 322. Each cutting segment 314 includes a leading edge 410 configured to engage engine components to remove material and form threads in the hole 218.

[0045] For further reference Figure 5 The flowchart illustrates the process for hole 218 ( Figure 2 The method for tapping is described. This method can begin at step 510. At step 510, the tapping bit 230 is mounted in the chuck 226, such that the tapping bit 230 is axially and rotatably stationary relative to the chuck 226. Then, the method can proceed to step 514.

[0046] At step 514, sensor 238 measures the thread teeth 322 of tapping drill bit 230 and sends a signal representing the measured value to control module 234. (Continue to refer to...) Figure 5 And refer to other sources. Figure 6 The provided example sensor 238 includes a shading gauge configured to scan or detect the profile of a tooth 322 in one of the cutting segments 314. Figure 6(Seen in solid line). Based on the input from sensor 238, control module 234 measures the thread pitch (P) of tapping drill bit 230. t ), thread pitch (P) t The thread pitch (P) is the axial distance between two adjacent peaks 326 of the thread tooth 322. In the provided example, sensor 238 and control module 234 measure the thread pitch (P) by measuring the axial distance between the peaks 326 of any two adjacent full teeth 322. t ).

[0047] Sensor 238 and control module 234 also measure a first distance (d1), which is the axial distance between the end face 318 and the peak 326 of any of the full teeth 322. Although the first distance (d1) is... Figure 6 The distance (d1) is shown as the distance from the first tooth in the full tooth 322, but the first distance (d1) can be the distance from any of the full teeth 322. The first distance (d1) is at the first rotational position (C1) of the tapping drill bit 230. Figure 4 The measurements are taken at the location shown in the diagram. The values ​​of the first rotational position (C1), the first distance (d1), and the thread pitch (P) of the tapping drill bit 230 are also considered. t The data can be stored in the memory of the control module 234, and the method can proceed to step 518.

[0048] At step 518, control module 234 can calculate the mathematical configuration of tooth 322 (i.e., the interpolation of the thread around tapping bit 230 up to end face 318) and calculate a hypothetical first tooth 610 as a tooth of the tapping bit, which, if not tapered or physically present, would otherwise have a peak 326 aligned axially with end face 318. This hypothetical first tooth 610 can be along one of the cutting segments 314, or can be rotatably positioned between the cutting segments 314. To calculate the hypothetical first tooth 610, control module 234 rotates the tap over-stroke (T... Rov The calculation is equal to the first distance (d1) divided by the thread pitch (P) of tooth 322. t ).

[0049] In other words: T Rov =d1 / P t

[0050] Then, the control module 234 is based on the tap rotation overshoot (T Rov ) and calculate the tap rotation offset (T) Roff Tap rotation offset (T) Roff ) can be equal to the tap rotation overshoot (T) Rov Subtract tap rotation overshoot (T) Rov The largest integer value of (T) Rov_intThen multiply by 360°. Tap rotation offset (T) Roff ) is the rotational offset from the first rotational position (C1) to the hypothetical rotational position of the first tooth 610. Tap rotational offset (T) Roff An example of that position in Figure 4 The middle axis (T) Roff The indication is given, but the actual rotation angle relative to the first rotational position (C1) can vary depending on the orientation of tooth 322 and the position from which the measurement is performed. Therefore, in Figure 4 The axis (T) in Roff The position of ) is only for illustrative purposes.

[0051] In other words: (T) Roff =(T Rov -T Rov_int )*360°)

[0052] Determining the tap rotation offset (T) Roff After that, the method can proceed to step 522, where the control module 234 can then determine the spark plug offset (S). off Spark plug offset (S) off The following will describe in more detail, but generally refers to the characteristics of spark plugs inserted into threaded holes, and the grounding strip 818 ( Figure 1 The location of the spark plug 14 is related to the thread of the spark plug 14 and the installation depth of the spark plug 14. In one configuration, the spark plug offset (S) off ) is a value previously stored in the memory of control module 234 and now retrieved from it. For example, spark plug offset (S off The value can be specified to the manufacturer of spark plug 14, and spark plug 14 can be manufactured within a specified tolerance for spark plug offset. In one example, spark plug 14 can be configured such that its spark plug offset (S) off The value is zero, but other values ​​can be used.

[0053] Or, spark plug offset (S off The value can be determined by measuring the characteristics of each spark plug 14. This can be done with any spark plug 14, such as when the spark plug offset is not specified to the manufacturer. This allows the thread tapping device 210 ( Figure 2 ) Customized for each individual spark plug, bore 218 ( Figure 2 Tapping is performed to ensure the correct orientation of each spark plug. Alternatively, it can be done as a way to check whether the spark plug offset is within the tolerance range specified on the spark plug, where the spark plug offset is specified in the manufacturing process to be within a certain tolerance range.

[0054] For further reference Figure 7 and Figure 10 The process of determining spark plug offset (S off The process can begin at step 1010, and the characteristics can be determined by the measuring device 710. The measuring device 710 can be connected to the thread tapping device 210. Figure 2 The measuring device 710 and the thread tapping device 210 can be separated, or the same device can be used to measure the spark plug 14 and the tapping bit 230. In the provided example, the measuring device 710 includes a chuck 714, a control module 718, and a sensor 722. In a configuration where the measuring device 710 and the thread tapping device 210 are separate devices, they can share a common control module, or their respective control modules can communicate with each other, or the user can record the spark plug offset (S) output by the measuring device 710. off And input the value into the thread tapping device 210.

[0055] At step 1010, spark plug 14 is held by chuck 714, and sensor 722 measures the characteristics of spark plug 14. Sensor 722 may be similar to sensor 238. Figure 2 and Figure 4 (See also...) Figure 8 Based on the input from sensor 722, control module 718 measures the thread pitch (P) of spark plug 14. s ), thread pitch (P) s The thread pitch (P) is the axial distance between two adjacent spikes 822 of the thread teeth 824 of the spark plug 14. In the provided example, the sensor 722 and the control module 718 measure the thread pitch (P) by measuring the axial distance between the spikes 822 of any two adjacent full teeth 824. s ).

[0056] Sensor 722 and control module 718 also measure a second distance (d2), which is the axial distance between the end face 826 of spark plug 14 and the spike 822 of any one of the teeth 824. Although the second distance (d2) is... Figure 8 The distance (d2) is shown as the distance from the second tooth of the full tooth 824, but the second distance (d2) can be the distance from any of the full teeth 824. The second distance (d2) is at the second rotational position (C2) of the spark plug 14. Figure 9 The measurement is taken at (shown in the diagram). Sensor 722 and control module 718 also measure the third rotational position (C3). Figure 9 As shown in the diagram, the third rotational position is the rotational offset from the second rotational position (C2) to the ground strip 818 of the spark plug 14. Figure 9In the example shown, the third rotational position is 180°, but this value will depend on the orientation of the grounding strip 818 relative to the position where the second distance (d2) measurement is performed. Sensor 722 and control module 718 also measure a third distance (d3), which is the distance between the end face 826 of spark plug 14 and the seat face 830 of spark plug 14. The seat face 830 is the surface that abuts against the shoulder 222 of bore 218. Figure 2 The values ​​of the second rotational position (C2), the second distance (d2), the third rotational position (C3), and the thread pitch (P) of the tapping drill bit 230. t The data can be stored in the memory of the control module 718, and the method can proceed to step 1014.

[0057] In the provided example, the teeth 824 of the spark plug 14 do not extend axially to the end face 826 and terminate at a position axially spaced from the end face 826. At step 1014, the control module 718 can calculate the mathematical configuration of the teeth 824 (i.e., the interpolation of the thread around the spark plug 14 up to the end face 826) and calculate a hypothetical first tooth 834, which, if physically present, would have a spike 822 that would otherwise be axially aligned with the end face 826. This hypothetical first tooth 834 can be rotatably positioned about the circumference of the spark plug, and for ease of illustration, in Figure 8 The image only shows alignment measured at the second distance (d2). To calculate the hypothetical first tooth 834, the control module 718 rotates the spark plug overshoot (S). Rov The calculation is equal to the second distance (d2) divided by the spark plug thread pitch (P). s ).

[0058] In other words: S Rov =d2 / P s

[0059] Then, the control module 718 is based on spark plug rotation overshoot (S Rov ) and calculate spark plug rotation offset (S) Roff Spark plug rotation offset can be equal to spark plug rotation overshoot (S). Rov Subtract spark plug spin overshoot (S) Rov The largest integer value of ) (S Rov_int ), then multiply by 360°. Spark plug rotation offset (S Roff ) is the rotational offset from the second rotational position (C2) to the hypothetical rotational position of the first tooth 834. Spark plug rotational offset (S) Roff An example of that position in Figure 9 The middle axis (S) RoffThe indication is given, but the actual rotation angle relative to the second rotational position (C2) can vary depending on the orientation of tooth 824 and the location of the measurement. Therefore, in Figure 9 The position of the axis (C3) is only for illustrative purposes.

[0060] In other words: S Roff =(S Rov -S Rov_int )*360°)

[0061] In determining the spark plug rotation offset (S) Roff After that, the method can proceed to step 1018, where the control module 718 calculates how to position the spark plug seat surface 830 on the shoulder 222. Figure 2 Number of rotations required (S) Rs The spark plug seat surface 830 is mounted on the shoulder 222. Figure 2 Number of rotations required (S) Rs The distance is equal to the third distance (d3) divided by the thread pitch of spark plug 14 (P). s ).

[0062] In other words: S Rs =d3 / P s

[0063] Determine the number of rotations (S) required to install spark plug 14. Rs After that, the method can proceed to step 1022, where the control module 718 bases its response on the number of rotations (S). Rs ) and calculate the spark plug reference completion position (S rfp Spark plug reference finish position (S) rfp This can be equal to the number of rotations (S) used to house spark plug 14. Rs Subtract the number of rotations (S) used to accommodate spark plug 14 Rs The largest integer value of ) (S Rs_int ), then multiply by 360°.

[0064] In other words: S rfp =(S Rs -S Rs_int )*360°

[0065] Determine the reference completion position of the spark plug (S) rfp After that, the method can proceed to step 1026, where the control module 718 is based on the spark plug reference completion position (S). rfp ) and spark plug rotation offset (S off The calculated electrode offset (E) off Completed electrode offset (E) off) equals spark plug rotation offset (S) Roff Add spark plug reference completion position (S) rfp ).

[0066] In other words: E off =S Roff +S rfp

[0067] After determining the completed electrode offset (E) off The method can proceed to step 1030, where the control module 718 is based on the second rotational position (C2), the third rotational position (C3), and the completed electrode offset (E). off ) and calculate spark plug offset (S) off Spark plug offset (S) off It can be equal to the third rotational offset (C3) minus the completed electrode offset (E). off Subtract the second rotation position (C2).

[0068] In other words: S off =C3-E off -C2

[0069] Back Figure 2 and Figure 5 Furthermore, given the spark plug offset, the tapping process for hole 218 can proceed to step 526. In step 526, the control module 234 calculates the initial orientation of the tap rotation (T). Rst Tap rotation initial orientation (T) Rst ) is based on the first rotational position (C1) and the tap rotation offset (T) Roff ) and spark plug offset (S off Tap rotation initial orientation (T) Rst ) can be equal to the adjustment factor (A) F Add the first rotational position (C1) and subtract the tap rotation offset (T) Roff Subtract spark plug offset (S) off Adjustment factor (A) F ) can be a positive or negative integer multiple of 0° or 360°, and is configured to cause the tap rotation to begin orientation (R). st Ultimately, it falls within the range of 0° to 360°.

[0070] In other words: R st =C1-T Roff -S off +A F

[0071] For example, if [C1-T] Roff -S off [>360°], then AF It can be -360°. If [C1-T] Roff -S off <0°], then A F It can be a perfect 360°. If [0°≤C1-T] Roff -S off If ≤360°], then A F It can be 0°. This adjustment factor (AF) can be used so that the thread tapping device 210 only needs to rotate the tapping drill bit 230 within the range of 0° to 360° to properly position it before tapping. Alternatively, the thread tapping device 210 can be configured to rotate the rotating drill bit 230 in the negative rotation direction or at a rate greater than 360° during the orientation of the tapping drill bit 230, and however, the adjustment factor can be omitted or set to 0° [360° ≤ C1-T]. Roff -S off ≤0°).

[0072] Determine the initial orientation of tap rotation (R) st After following the method, the process can proceed to step 530, in which the control module 234 rotates the tapping drill bit 230 so that it rotates to the tap rotation starting orientation (R). st The control module 234 also positions the tap 230 such that the end face 318 of the tap 230 is a pitch increment distance away from the hole 218, which is equal to an integer multiple of the thread pitch of the tapping drill bit 230 (P). t With the tapping drill bit 230 oriented relative to the hole 218, the method can proceed to step 534.

[0073] At step 534, the thread tapping device 210 synchronizes the rotational speed of the tapping drill bit 230 and the axial feed rate of the tapping drill bit 230 toward the hole 218 with the thread pitch (P) of the tapping drill bit 230. t Continue to rotate and move the drill bit 230 to cut internal threads in the hole 218.

[0074] When the spark plug 14 is screwed into and placed in the cylinder head 10, the internal threads are formed using the above-described device and method to ensure the desired orientation of the ground strip 818 of each spark plug 14.

[0075] Although terms like "after" are used to discuss the steps of the methods discussed above in a specific order, it should be understood that some calculations may be performed simultaneously or in a different order than that specifically described above.

[0076] The description in this disclosure is exemplary in nature only, and therefore, variations without departing from the spirit and scope of this disclosure are intended to fall within its scope. These variations should not be considered as departing from the spirit and scope of this disclosure.

[0077] In this application, including the following definitions, the term "module" or "controller" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include the following: application-specific integrated circuit (ASIC); digital, analog, or mixed-signal analog / digital discrete circuit; digital, analog, or mixed-signal analog / digital integrated circuit; combinational logic circuit; field-programmable gate array (FPGA); processor circuitry (shared, dedicated, or grouped) that executes code; memory circuitry (shared, dedicated, or grouped) that stores code executed by the processor circuitry; other suitable hardware components that provide the aforementioned functionality; or combinations of some or all of the above, such as in a system-on-a-chip.

[0078] A module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces that connect to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given module in this disclosure may be distributed across multiple modules connected via the interface circuits. For example, multiple modules may allow for load balancing. In another example, a server (also referred to as a remote or cloud) module may perform some functionality under the guise of a client module.

[0079] The term "code" as used above can include software, firmware, and / or microcode, and can refer to programs, routines, functions, categories, data structures, and / or targets. The term "common processor circuitry" covers a single processor circuitry that executes some or all of the code from multiple modules. The term "group processor circuitry" covers a processor circuitry that, in conjunction with additional processor circuitry, executes some or all of the code from one or more modules. The term "multiple processor circuitry" covers multiple processor circuitry on a discrete chip, multiple processor circuitry on a single chip, multiple cores of a single processor circuitry, multiple threads of a single processor circuitry, or a combination of the above. The term "common memory circuitry" covers a single memory circuitry that stores some or all of the code from multiple modules. The term "group memory circuitry" covers a memory circuitry that, in conjunction with additional memory, stores some or all of the code from one or more modules.

[0080] The term memory circuit can be a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not cover transient electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); therefore, the term computer-readable medium can be considered tangible and non-transient. Non-limiting examples of non-transient tangible computer-readable media are non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or mask read-only circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital magnetic tape or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0081] The apparatus and methods described in this application can be implemented, in part or in whole, by a dedicated computer configured to execute one or more specific functions embodied in a computer program. Functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs by the routine work of a skilled technician or programmer.

[0082] A computer program includes processor-executable instructions stored on at least one non-transitory tangible computer-readable medium. A computer program may also include or depend on stored data. A computer program may encompass a basic input / output system (BIOS) that interacts with the hardware of a special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0083] Computer programs may include: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language) or XML (Extensible Markup Language); (ii) assembly code; (iii) object code generated from source code by a compiler; (iv) source code executed by an interpreter; and (v) source code compiled and executed by a just-in-time (JIT) compiler, etc. As an example only, source code can be written using syntax from languages ​​including: C, C++, C#, Objective C, Haskel, Go, SQL, R, Lisp, etc. Fortran, Perl, Pascal, Curl, OCaml, HTML5, Ada, ASP (Active Server Pages), PHP, Scala, Eiffel, Smalltalk, Erlang, Ruby Visual Lua and

[0084] The elements described in the claims are not intended to be devices plus functional elements in the sense of 35 U.S.SC §112(f), unless an element is explicitly described using the phrase “component for…” or in the case of a method claim using the phrase “operation for…” or “steps for…”.

[0085] According to the present invention, a method for tapping an engine component to orient a spark plug in the combustion chamber of an internal combustion engine includes: mounting a tap to a tool head; measuring the thread pitch of the tap; measuring a first distance between the end surface of the tap and the center of a predetermined full tooth of the tap, the first distance being measured at a first rotational position of the tap; calculating an imaginary first tooth of the tap based on the thread pitch and the first distance; and determining the distance from the first rotational position to the point where the end surface of the tap is at the large diameter of the imaginary first tooth of the tap. The tap rotation offset at the first intersecting rotation position; determining the spark plug offset; calculating the tap rotation starting orientation, which is equal to the first rotation position minus the tap rotation offset minus the spark plug offset; rotating the tool head to the rotation starting orientation; positioning the tap such that the end surface of the tap is the pitch increment distance of the tap away from the engine component; and synchronizing the rotational speed of the tool head and the feed rate of the engine component relative to the tool head to the thread pitch of the tap and operating the tool to cut or form threads in the engine component.

[0086] According to one embodiment, the invention is further characterized in that a mathematical configuration of the teeth extending from the predetermined full teeth of the tap to the end surface of the tap is calculated based on the thread pitch of the tap and the first distance, the mathematical configuration of the teeth including the hypothetical first tooth.

[0087] According to one embodiment, determining the spark plug offset includes measuring parameters of the spark plug and calculating the spark plug offset based on the parameters of the spark plug.

[0088] According to one embodiment, determining the spark plug offset includes: measuring the thread pitch of the spark plug; measuring a second distance between the end surface of the spark plug and the center of a predetermined tooth of the spark plug, the second distance being measured at a second rotational position of the spark plug; measuring a third distance between the end surface of the spark plug and the seat of the spark plug; calculating an imaginary first tooth of the spark plug based on the thread pitch of the spark plug and the second distance; and calculating the spark plug offset based on the imaginary first tooth of the spark plug, the third distance, and the second rotational position.

[0089] According to one embodiment, the tap has a thread that is chamfered toward the end surface of the tap.

[0090] According to one embodiment, the tap includes a plurality of partial threads near the end surface of the tap.

[0091] According to one embodiment, a laser tool is used to set a gauge or a shadow gauge to measure the thread pitch of the tap and the first distance.

[0092] A method for tapping an engine component to orient a spark plug in the combustion chamber of an internal combustion engine includes: mounting a tap to a tool head; measuring the thread pitch of the tap; measuring a first distance between the end face of the tap and the center of a predetermined tooth of the tap, the first distance being measured at a first rotational position of the tap; calculating tap rotational overshoot, the tap rotational overshoot being equal to the first distance divided by the thread pitch of the tap; and calculating tap rotational offset, the tap rotational offset being equal to the tap rotational overshoot minus the largest integer value of the tap rotational overshoot. Then multiply by 360°; determine the spark plug offset; calculate the tap rotation starting orientation, which is based on the first rotation position, the tap rotation offset, and the spark plug offset; rotate the tool head to the tap rotation starting orientation; position the tap such that the end surface of the tap is the pitch increment distance of the tap away from the engine component; and synchronize the rotational speed of the tool head and the feed rate of the engine component relative to the tool head to the thread pitch of the tap and operate the tool to cut threads in the engine component.

[0093] According to one embodiment, determining the spark plug offset includes measuring parameters of the spark plug and calculating the spark plug offset based on the parameters of the spark plug.

[0094] According to one embodiment, determining the spark plug offset includes: measuring the thread pitch of the spark plug; measuring a second distance between the end surface of the spark plug and the center of a predetermined tooth of the spark plug, the second distance being measured at a second rotational position of the spark plug; measuring a third rotational position, the third rotational position being the rotational offset from the second rotational position to the ground strip of the spark plug; measuring a third distance between the end surface of the spark plug and the seat of the spark plug; calculating spark plug rotational overshoot, the spark plug rotational overshoot being equal to the second distance divided by the thread pitch of the spark plug; and calculating spark plug rotational offset, the spark plug rotational offset being equal to the spark plug rotational overshoot minus the spark plug... The maximum integer value of the rotational overshoot is multiplied by 360°; the number of rotations for placing the spark plug is calculated, which is equal to the third distance divided by the thread pitch of the spark plug; the reference completion position of the spark plug is calculated, which is equal to the number of rotations for placing the spark plug minus the maximum integer value of the number of rotations for placing the spark plug, and then multiplied by 360°; the completed electrode offset is calculated, which is equal to the spark plug rotational offset plus the reference completion position of the spark plug; and the spark plug offset is calculated, which is equal to the third rotational offset minus the completed electrode offset minus the second rotational position.

[0095] According to one embodiment, the third rotational offset is equal to 0°.

[0096] According to one embodiment, the tap has a thread that is chamfered toward the end surface of the tap.

[0097] According to one embodiment, the tap includes a plurality of partial threads near the end surface of the tap.

[0098] According to one embodiment, the predetermined tooth is a full tooth.

[0099] According to one embodiment, a laser tool is used to set a gauge or a shadow gauge to measure the thread pitch of the tap and the first distance.

[0100] According to one embodiment, the initial orientation of the tap rotation is equal to the adjustment factor plus the first rotation position minus the tap rotation offset minus the spark plug offset.

[0101] According to one embodiment, the adjustment factor is a positive or negative integer multiple of 0° or 360°, and is configured such that the initial orientation of the tap rotation is within the range of 0° to 360°.

[0102] According to the present invention, a threading device is provided, the threading device comprising: a tool including a chuck configured to rotate about an axis; a tap coupled to the chuck to rotate together about the axis; at least one sensor configured to detect the thread pitch of the tap and a first distance between the end surface of the tap and the center of a predetermined full tooth of the tap, the first distance being measured at a first rotational position of the tap; and a control module communicating with the at least one sensor and the tool, the control module being configured to... The position of a hypothetical first tooth is calculated based on the thread pitch of the tap and the first distance, the end surface of which intersects the hypothetical first tooth at the large diameter of the hypothetical first tooth. The control module is configured to calculate the tap rotational initiation orientation based on the first rotational position, the position of the hypothetical first tooth, and the spark plug offset. The control module communicates with the tool and is configured to synchronize the rotational speed of the chuck and the feed rate of the engine component relative to the chuck to the thread pitch of the tap, so as to cut or form threads in the engine component based on the tap rotational initiation orientation.

[0103] According to one embodiment, the control module is configured to control the axial position of the tap relative to the engine component based on an input representing the total length of the tap and the first rotational position.

Claims

1. A method for tapping engine components to orient spark plugs in the combustion chamber of an internal combustion engine, the method comprising: Install the tap onto the tool head; Measure the thread pitch of the tap; Measure a first distance between the end surface of the tap and the center of a predetermined full tooth of the tap, the first distance being measured at a first rotational position of the tap; The imaginary first tooth of the tap is calculated based on the thread pitch and the first distance; Determine the tap rotation offset from the first rotation position to the rotation position where the end surface of the tap intersects the imaginary first tooth of the tap at the large diameter of the imaginary first tooth of the tap; Determine spark plug offset; Calculate the initial orientation of the tap rotation, where the initial orientation of the tap rotation is equal to the first rotation position minus the tap rotation offset minus the spark plug offset; Rotate the tool head to the rotation start orientation; Position the tap such that the end surface of the tap is the pitch increment distance of the tap away from the engine component; as well as The rotational speed of the tool head and the feed rate of the engine component relative to the tool head are synchronized to the thread pitch of the tap, and the tool is operated to cut or form threads in the engine component.

2. The method of claim 1, further comprising: A mathematical configuration of the teeth extending from the predetermined full teeth of the tap to the end surface of the tap is calculated based on the thread pitch of the tap and the first distance, the mathematical configuration of the teeth including the hypothetical first tooth.

3. The method of claim 1, wherein determining the spark plug offset includes measuring parameters of the spark plug and calculating the spark plug offset based on the parameters of the spark plug.

4. The method of claim 1, wherein determining the spark plug offset comprises: Measure the thread pitch of the spark plug; Measure a second distance between the end surface of the spark plug and the center of a predetermined tooth of the spark plug, the second distance being measured at a second rotational position of the spark plug; Measure the third distance between the end surface of the spark plug and the seat of the spark plug; The imaginary first tooth of the spark plug is calculated based on the thread pitch of the spark plug and the second distance; as well as The spark plug offset is calculated based on the hypothetical first tooth, the third distance, and the second rotational position of the spark plug.

5. The method of claim 4, wherein determining the spark plug offset comprises: Calculate the spark plug rotation overshoot, whereby the spark plug rotation overshoot is equal to the second distance divided by the thread pitch of the spark plug; Calculate the spark plug rotation offset, which is equal to the spark plug rotation overshoot minus the maximum integer value of the spark plug rotation overshoot, and then multiplied by 360°; Calculate the number of rotations required to position the spark plug, wherein the number of rotations required to position the spark plug is equal to the third distance divided by the thread pitch of the spark plug; Calculate the spark plug reference completion position, which is equal to the number of rotations used to place the spark plug minus the maximum integer value of the number of rotations used to place the spark plug, and then multiply by 360°; The calculated electrode offset is equal to the spark plug rotation offset plus the spark plug reference position. as well as Calculate the spark plug offset, which is equal to the third rotation offset minus the completed electrode offset minus the second rotation position.

6. The method of claim 5, wherein the third rotational offset is equal to 0°.

7. The method of claim 1, wherein the tap has a thread with a chamfer toward the end surface of the tap.

8. The method of claim 1, wherein the tap includes a plurality of partial threads near the end surface of the tap.

9. The method of claim 1, wherein a laser tool is used to set a gauge or a shadow gauge to measure the thread pitch of the tap and the first distance.

10. The method of claim 1, wherein calculating the imaginary first tooth of the tap includes calculating the tap rotational overshoot, the tap rotational overshoot being equal to the first distance divided by the thread pitch of the tap.

11. The method of claim 10, wherein the tap rotation offset is equal to the tap rotation overshoot minus the maximum integer value of the tap rotation overshoot, and then multiplied by 360°.

12. A threading device, the threading device comprising: The tool includes a chuck configured to rotate about an axis; A tap, which is connected to the chuck to rotate together about the axis; At least one sensor is configured to detect the thread pitch of the tap and a first distance between the end surface of the tap and the center of a predetermined full tooth of the tap, the first distance being measured at a first rotational position of the tap; as well as A control module, communicating with the at least one sensor and the tool, is configured to calculate the position of a hypothetical first tooth based on the thread pitch of the tap and the first distance, the end surface of which intersects the hypothetical first tooth at its large diameter; the control module is configured to calculate the tap rotational initiation orientation based on the first rotational position, the position of the hypothetical first tooth, and the spark plug offset; the control module communicates with the tool and is configured to synchronize the rotational speed of the chuck and the feed rate of the engine component relative to the chuck to the thread pitch of the tap, so as to cut or form threads in the engine component based on the tap rotational initiation orientation.

13. The threading device of claim 12, wherein the control module is configured to control the axial position of the tap relative to the engine component based on an input representing the total length of the tap and the first rotational position.

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