CN103868469B - Full automatic following tracking precise scanning detecting device and method for camshaft complex molded-line lift - Google Patents

Abstract

The present invention provides a camshaft complex type line lift full-automatic follow-up tracking precision scanning detection device and method: it includes a measuring head, a servo follow-up unit and a scalable free follow-up unit, which is driven by the servo follow-up unit and installed in a free place. The probe on the servo unit approaches and touches the camshaft, or the probe on the servo servo unit moves close to and contacts the camshaft with the movement of the servo servo unit. During the rotation of the camshaft, according to the The position change information of the camshaft lift change adjusts the servo servo unit in real time, so that the free servo unit is always in the middle of the stroke under the premise of keeping the probe in contact with the camshaft. The lift trajectory of the camshaft in the equipment coordinate system, the servo servo unit and the free servo unit probe work together during the measurement process, which not only improves the detection range, but also reduces the friction between the probe and the camshaft under test. Reduced wear on the camshaft during measurement.

Description

Camshaft complex line lift automatic follow-up tracking precision scanning detection device and method

technical field

The invention belongs to the field of precision measurement of complex profiles, and in particular relates to a fully automatic follow-up tracking precision scanning detection device and method for complex profile lift of a camshaft.

Background technique

The camshaft is one of the core components of the piston engine. Its function is to control the opening and closing of the valve to ensure sufficient intake and exhaust of the cylinder. Considering the durability of the engine and the smoothness of operation, the valve should not produce too much or too much impact due to the acceleration and deceleration process in the opening and closing action, otherwise it will cause serious wear of the valve, increased noise or other serious consequences. Therefore, the camshaft is directly related to the power, torque output and running smoothness of the engine. It directly affects the power and running characteristics of an engine. The manufacturing accuracy and level of the camshaft are particularly important in the precision manufacturing of the engine. . The precise detection technology of the camshaft profile is one of the essential technical means to realize the high-precision manufacturing of the camshaft. Therefore, with the increasing requirements of engine performance in equipment manufacturing, the precision detection technology of camshaft profile has a very important position in the precision manufacturing process of engines.

The camshaft profile is generally designed according to the motion law of the valve and the motion characteristics of the engine. The form is very complicated. The precise measurement of it mainly realizes the following two important applications: one is used as the final inspection of the camshaft manufacturing accuracy to realize the quality of the camshaft processing Control; the second is to measure the actual lift trajectory of the camshaft according to the needs of high-precision repairing of the engine, and realize the precise interchangeability surveying and mapping of the camshaft. As a complex shaft, the camshaft has a large lift, and it is generally difficult to directly obtain the lift information due to the range problem of the commonly used micro-displacement sensor.

Contents of the invention

The object of the present invention is to provide a full-automatic follow-up tracking precision scanning detection device and method for complex camshaft profile lift.

To achieve the above object, the present invention adopts the following technical solutions:

A camshaft complex type line lift automatic follow-up precision scanning detection device, including a follow-up tracking precision scanning probe system, the follow-up tracking precision scanning probe system includes a probe, a servo follow-up unit and a retractable free servo unit, the free servo unit can move with the servo servo unit, and the probe is set on the free servo unit, or the servo servo unit can follow the free servo unit, and the probe is set on the servo servo unit superior.

The servo follow-up unit includes a first slide plate driven by a servo motor, the free follow-up unit includes a second slide plate and a spring, the second slide plate is arranged on the first slide plate, one end of the spring is connected with the first slide plate, and the other end is connected with the second slide plate. The two slide plates are connected, the measuring head is set on the second slide plate, and grating rulers are respectively set on the first slide plate and the second slide plate.

The follow-up tracking precision scanning probe system also includes a base plate, a first linear guide rail, a lead screw and a second linear guide rail, the lead screw and the first linear guide rail are arranged on the base plate, and the first slide plate and the first linear guide rail connected, the servo motor is connected with the first slide plate through the lead screw, the second linear guide is arranged on the first slide, and the second slide is connected with the second linear guide.

The servo follow-up unit includes a first slide plate driven by a servo motor, the free follow-up unit includes a second slide plate and a spring, one end of the spring is fixed, the other end is connected to the second slide plate, the measuring head is arranged on the first slide plate, and the second slide plate A slide plate is arranged on the second slide plate, and grating rulers are respectively set on the first slide plate and the second slide plate.

The follow-up tracking precision scanning probe system also includes a base plate, a first linear guide rail, a screw and a second linear guide rail, the second linear guide rail is arranged on the base plate, the second slide plate is connected with the second linear guide rail, and the first linear guide rail is connected to the second linear guide rail. The linear guide rail and the lead screw are arranged on the second slide plate, the first slide plate is connected with the first linear guide rail, and the servo motor is connected with the first slide plate through the lead screw.

The device also includes a drive control assembly, which includes a host computer, a grating scale for detecting the position changes of the free servo unit and the servo servo unit, and a circular grating for detecting the rotation information of the camshaft. The reading head of the grating scale, the reading head of the circular grating and the servo motor for driving the servo servo unit are connected.

The detection method of the above-mentioned camshaft complex profile lift automatic follow-up precision scanning detection device includes the following steps:

Drive the probe set on the free servo unit to approach and contact the camshaft through the servo servo unit, or, the probe on the servo servo unit moves close to and contacts the camshaft with the movement of the servo servo unit; then through the precision rotary shaft The system makes the camshaft rotate. During the rotation of the camshaft, the position of the servo servo unit is adjusted in real time according to the position change of the free servo unit with the change of the camshaft lift, so that the free servo unit maintains the measuring head and the cam Under the premise that the shaft is in contact, it is always in the middle of the stroke; at the same time, the displacement information of the free servo unit and the servo servo unit and the rotation information of the camshaft are collected synchronously, and the displacement information of the free servo unit and the servo servo unit collected synchronously The information is superimposed, and then combined with the synchronously collected rotation information of the camshaft to obtain the profile data of the camshaft.

The beneficial effects of the present invention are reflected in:

The servo tracking precision scanning probe system of the present invention includes a probe, a servo servo unit and a retractable free servo unit. The servo servo unit and the free servo unit work together during the measurement process, which not only improves the detection range , It also reduces the friction between the probe and the camshaft to be tested, and reduces the wear on the camshaft during the measurement process.

Description of drawings

Fig. 1 is the overall structural representation of the present invention;

Figure 2 is one of the structural schematic diagrams of the servo tracking precision scanning probe system of the present invention (the probe is connected to the free servo unit);

Fig. 3 is the second structural diagram of the servo tracking precision scanning probe system of the present invention (the probe is connected to the free servo unit);

Figure 4 is the third schematic diagram of the structure of the servo tracking precision scanning probe system of the present invention (the probe is connected to the servo servo unit);

5 is a schematic structural diagram of the drive control assembly of the present invention;

In the figure: 1 is the base, 2 is the column, 3 is the top of the tailstock, 4 is the precision rotary shaft system, 5 is the follow-up tracking precision scanning probe system, 6 is the first linear guide rail, 7 is the first slide plate, 8 is the screw, 9 is the servo motor, 10 is the second linear guide, 11 is the second slide, 12 is the probe, 13 is the spring, 14 is the grating ruler, 15 is the base plate, 16 is the Z-axis motor, 17 is the column Slide plate, 18 are workpiece clamping motors.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

Referring to FIG. 1 , the camshaft complex type line lift automatic follow-up precision scanning detection device of the present invention includes a follow-up tracking precision scanning probe system 5, and the follow-up tracking precision scanning probe system 5 includes a probe 12 , a servo follow-up unit and a scalable free follow-up unit, the free follow-up unit can follow the movement of the servo follow-up unit, the probe 12 is set on the free follow-up unit (see Figure 2-Figure 3), or the servo follow-up unit The unit can move following the free servo unit, and the probe 12 is set on the servo servo unit (see Figure 4).

The camshaft adopts a vertical or horizontal clamping method; for the vertical clamping method, the device also includes a base 1, a column 2, a tailstock tip 3 and a precision rotary shaft system 4 for clamping the camshaft, The precision rotary shaft system 4 and the column 2 are set on the base 1, the tailstock tip 3 and the tracking precision scanning probe system 5 are set on the column 2, the tailstock tip 3 and the tracking precision scanning probe system 5 can be Move up and down along the column 2 (tailstock top 3 and follow-up tracking precision scanning probe system 5 are respectively set on the corresponding column slide 17, and the workpiece clamping motor 18 and Z-axis motor 16 respectively drive the corresponding column slide 17 to realize the The above-mentioned up and down movement), the precision rotary shaft system 4 is provided with a circular grating.

Referring to Fig. 2 and Fig. 3, described servo follow-up unit comprises the first slide plate 7 driven by servo motor 9, and free follow-up unit comprises the second slide plate 11 and spring 13, and the second slide plate 11 is arranged on the first slide plate 7, One end of the spring 13 is connected with the first slide plate 7, and the other end is connected with the second slide plate 11. The measuring head 12 is arranged on the second slide plate 11. The first slide plate 7 and the second slide plate 11 are respectively provided with a grating scale 14. The follow-up tracking precision scanning probe system 5 also includes a base plate 15, a first linear guide 6, a lead screw 8 and a second linear guide 10, the lead screw 8 and the first linear guide 6 are arranged on the base 15, the second A slide plate 7 is connected to the first linear guide 6, the servo motor 9 is connected to the first slide 7 through a screw 8, the second linear guide 10 is arranged on the first slide 7, and the second slide 11 is connected to the second linear guide 10 .

Or, referring to Fig. 4, described servo follow-up unit comprises the first slide plate 7 driven by servomotor 9, and free follow-up unit comprises second slide plate 11 and spring 13, and one end of spring 13 is fixed, and the other end and second slide plate 11 Connected, the probe 12 is set on the first slide 7, the first slide 7 is set on the second slide 11, and the first slide 7 and the second slide 11 are respectively provided with a grating ruler 14. The follow-up tracking precision scanning probe system 5 also includes a base plate 15, a first linear guide rail 6, a screw 8 and a second linear guide rail 10, the second linear guide rail 10 is arranged on the base plate 15, the second slide plate 11 and the second linear guide rail 10 The two linear guide rails 10 are connected, the first linear guide rail 6 and the lead screw 8 are arranged on the second slide plate 11, the first slide plate 7 is connected with the first linear guide rail 6, and the servo motor 9 is connected with the first slide plate 7 through the lead screw 8 .

Referring to Fig. 5, the device also includes a drive control assembly, which includes a host computer (the computer and software system are collectively referred to as the host computer), a grating ruler 14 ( That is, the grating rulers set on the first slide and the second slide respectively), the circular grating used to detect the rotation information of the camshaft (that is, the circular grating set on the precision rotary shaft system), the reading head of the host computer and the grating ruler, the circular grating The reading head and the servo motor 9 used to drive the servo follow-up unit are connected; the drive control assembly also includes a driver, a motion control card and a counting card, and the servo motor 9 is used to drive the follow-up tracking precision scanning probe system 5 The Z-axis motor that moves up and down and the W-axis motor in the precision rotary shaft system are respectively connected to the motion control card through the driver, and the motion control card is connected to the host computer. The readings of the grating scale and the circular grating are collected and transmitted to the The upper computer.

The detection method of the above-mentioned camshaft complex profile lift automatic follow-up precision scanning detection device includes the following steps:

1) Clamp the workpiece (camshaft) between the top of the tailstock and the precision rotary shaft system, and establish a polar coordinate system with the rotation center of the workpiece as the origin;

2) To determine the reference point, the specific methods include the following three:

(1) Low point detection method based on the keyway: Use the flat probe (Figure 3) to measure the journal radius of the keyway section of the camshaft, rotate the camshaft once, measure the polar diameter value of the journal of the workpiece, and the minimum value in the measurement results The position is the center position of the keyway, and this position is taken as the zero position of the phase.

(2) High point detection method based on the keyway: process arc tooling, install it at the position of the keyway of the camshaft and protrude from the journal of this section, rotate the camshaft once and measure the polar diameter value of the journal of this section of the camshaft, the largest of the measurement results The value position is the center position of the keyway, and this position is taken as the zero position of the phase.

(3) Using the pin as the reference high point detection method: install the pin at the position of the pin hole of the camshaft, design the anti-seize fixture part, and install it at the pin position. The part and the pin form a similar cam structure, and the probe measures the profile of this part. The highest point in the calculation is the phase zero.

3) Drive the probe 12 set on the free servo unit to approach and contact the camshaft through the servo servo unit (see Figure 2-3), or, the probe 12 on the servo servo unit follows the movement of the servo servo unit Move close to and contact the camshaft (see Figure 4); then make the camshaft rotate through the precision rotary shaft system 4, and adjust in real time according to the position change of the free follower unit with the change of the camshaft lift during the rotation of the camshaft The position of the servo follow-up unit makes the free follow-up unit always in the middle of the stroke under the premise of keeping the probe 12 in contact with the camshaft; at the same time, the displacement information of the free follow-up unit and the servo follow-up unit and the camshaft The rotation information of the camshaft is superimposed on the synchronously collected free servo unit and the displacement information of the servo servo unit, and then combined with the synchronously collected camshaft rotation information to obtain the camshaft profile data.

The change of the lift of the camshaft leads to the change of the position of the probe, which in turn causes the reading of the grating scale on the free follow-up unit to change. The reading of the grating ruler sends an instruction to the motion control card, and the motion control card controls the servo motor to move, which in turn causes the readings of the grating ruler on the free servo unit and the grating ruler on the servo servo unit to change, and the servo servo unit on the The reading of the grating ruler is divided into two channels, one of which enters the motion control card and the servo motor to form a closed-loop control. The other route is collected by the counting card, and then superimposed with the currently collected grating ruler reading of the free follow-up unit, so as to obtain the measured camshaft lift data.

4) After superimposing the data of the two grating rulers obtained by the tracking precision scanning probe system, combined with the angle information of the circular grating collected synchronously, the profile data of the camshaft is obtained. The various errors of the camshaft can be obtained by processing the data.

Example

A camshaft complex line lift automatic follow-up precision scanning detection device, the device includes a follow-up tracking precision scan probe system, a precision rotary shaft system, a tailstock top and a drive control assembly.

Follow-up tracking precision scanning probe system includes three parts: free follow-up unit, servo follow-up unit and probe: the probe is a part in contact with the workpiece (camshaft), and the front end of the probe system is a free follow-up unit, free follow-up The unit includes a rigid spring and a slide plate. The linear motion of the slide plate of the free follow-up unit is realized through a high-precision linear guide. The probe is set on the slide plate of the free follow-up unit. The rigid spring keeps the probe and the workpiece in constant contact. High resolution and high precision grating ruler for position measurement. The free follow-up unit solves the follow-up tracking problem of the cam profile during the measurement process. The rear end of the measuring head system is a servo follow-up unit, which includes a slide plate, and the servo motor controls the screw to drive the slide plate of the servo follow-up unit to realize a linear motion parallel to the free follow-up unit at the front end on the corresponding high-precision linear guide rail ( The linear accuracy of the whole length is less than 1um), the motion stroke is 100mm, and the position is also recorded by a high-precision grating ruler with a resolution of 0.1um (uncertainty 3um/m). When detecting workpieces, the free follow-up unit and the servo follow-up unit work together to keep the free follow-up unit in the middle of the stroke. When the probe is close to the workpiece, the servo servo unit realizes the adaptive speed control of the probe according to the distance from the workpiece, so as to realize the rapid approach of the probe and effectively prevent the collision with the surface of the camshaft. During the detection process, the servo follow-up unit is adjusted in time through the reading of the grating ruler, so that the free follow-up unit is always in the middle of the stroke, realizing closed-loop control. The control strategy of the servo follow-up unit can be divided into two trajectory control modes: follow-up control and known model planning.

The order of the free follow-up unit and the servo follow-up unit can be interchanged, that is, the contact with the probe can be either a free follow-up unit or a servo follow-up unit.

During detection, all parts of the probe system work together to achieve accurate acquisition of the camshaft lift trajectory. The free follower unit keeps the probe tip in contact with the camshaft surface by the action of a spring. As the workpiece rotates (the workpiece is clamped between the top of the tailstock and the precision rotary shaft system, and is driven by the precision rotary shaft system), the free follow-up unit changes its position with the change of the lift, and the moving position information is captured by the free follow-up unit The grating scale is used for measurement, and it is fed back to the drive control component at the same time. The drive control component adjusts the servo motor in real time according to the position information, so that the free follow-up unit can always keep the free follow-up unit in the stroke under the premise of ensuring the contact between the probe and the workpiece. centre position.

The present invention adopts the multi-axis grating synchronous latching technology, utilizes the data acquisition card in the host computer, realizes the grating synchronous counting of the free follow-up unit, the servo follow-up unit and the precision rotary shaft system, ensures the synchronization of relevant position information, and simultaneously passes through etc. Angle latch sampling measurement ensures effective comparison of lift accuracy.

Claims (8)

1. a kind of camshaft complexity molded line lift full-automatic servo follow-up tracing precision sweep detection means it is characterised in that：This device Including servo follow-up tracing precision sweep gauge head system (5), described servo follow-up tracing precision sweep gauge head system (5) include gauge head (12), Servo with moving cell, freely can be followed servo with moving cell and move with moving cell with moving cell and telescopic freedom；

Described servo includes the first slide plate (7) being driven by servomotor (9) with moving cell, freely includes second with moving cell sliding Plate (11) and spring (13), the second slide plate (11) is arranged on the first slide plate (7), one end of spring (13) and the first slide plate (7) be connected, the other end is connected with the second slide plate (11), and gauge head (12) is arranged on the second slide plate (11), the first slide plate (7) and Grating scale (14) is respectively arranged with the second slide plate (11)；

In the rotation process of camshaft, watched with the change in location real-time adjustment that camshaft lift changes with moving cell according to free Clothes, with the position of moving cell, make freely to be in stroke with moving cell all the time on the premise of keeping gauge head (12) to contact with camshaft Centre position.

2. a kind of camshaft complexity molded line lift full-automatic servo follow-up tracing precision sweep detection means according to claim 1, It is characterized in that：Described servo follow-up tracing precision sweep gauge head system (5) also includes base plate (15), first straight line guide rail (6), leading screw (8) and second straight line guide rail (10), leading screw (8) and first straight line guide rail (6) are arranged on base plate (15), the first slide plate (7) it is connected with first straight line guide rail (6), servomotor (9) is connected with the first slide plate (7) by leading screw (8), second straight line guide rail (10) it is arranged on the first slide plate (7), the second slide plate (11) is connected with second straight line guide rail (10).

3. a kind of camshaft complexity molded line lift full-automatic servo follow-up tracing precision sweep detection means according to claim 1, It is characterized in that：Described device also includes drive control assembly, and described drive control assembly includes host computer, is used for detecting freedom With the grating scale (14) of moving cell and the change of servo servo-actuated cell position, the Circular gratings for detecting cam axle information, Host computer and the read head of grating scale, the read head of Circular gratings and for driving servo with servomotor (9) phase of moving cell Even.

4. a kind of inspection of camshaft complexity molded line lift full-automatic servo follow-up tracing precision sweep detection means as claimed in claim 1 Survey method it is characterised in that：Comprise the following steps：

Driven with moving cell by servo be arranged at freely with the gauge head (12) on moving cell near and contact camshaft；Then lead to Crossing precision rotating shafting (4) makes described cam axle, in the rotation process of camshaft, according to freedom with moving cell with cam The change in location real-time adjustment servo of axle lift variation with the position of moving cell, make freely with moving cell keep gauge head (12) with All the time it is in the centre position of stroke on the premise of camshaft contact；Meanwhile, synchronous acquisition freely with moving cell and servo with The displacement information of moving cell and the rotation information of camshaft, by the freedom of synchronous acquisition with moving cell and servo with moving cell Displacement information is superimposed, and the rotation information then in conjunction with the camshaft of synchronous acquisition obtains the outline data of camshaft.

5. a kind of camshaft complexity molded line lift full-automatic servo follow-up tracing precision sweep detection means it is characterised in that：This device Including servo follow-up tracing precision sweep gauge head system (5), described servo follow-up tracing precision sweep gauge head system (5) include gauge head (12), Servo with moving cell and telescopic freedom with moving cell, can follow with moving cell and freely move with moving cell by servo；

Described servo includes the first slide plate (7) being driven by servomotor (9) with moving cell, freely includes second with moving cell sliding Plate (11) and spring (13), one end of spring (13) is fixed, and the other end is connected with the second slide plate (11), and gauge head (12) is arranged at On first slide plate (7), the first slide plate (7) is arranged on the second slide plate (11), and the first slide plate (7) and the second slide plate (11) above divide It is not provided with grating scale (14)；

In the rotation process of camshaft, watched with the change in location real-time adjustment that camshaft lift changes with moving cell according to free Clothes, with the position of moving cell, make freely to be in stroke with moving cell all the time on the premise of keeping gauge head (12) to contact with camshaft Centre position.

6. a kind of camshaft complexity molded line lift full-automatic servo follow-up tracing precision sweep detection means according to claim 5, It is characterized in that：Described servo follow-up tracing precision sweep gauge head system (5) also includes base plate (15), first straight line guide rail (6), leading screw (8) and second straight line guide rail (10), second straight line guide rail (10) is arranged on base plate (15), and the second slide plate (11) is straight with second Line guide rail (10) is connected, and first straight line guide rail (6) and leading screw (8) are arranged on the second slide plate (11), the first slide plate (7) and the One line slideway (6) is connected, and servomotor (9) is connected with the first slide plate (7) by leading screw (8).

7. a kind of camshaft complexity molded line lift full-automatic servo follow-up tracing precision sweep detection means according to claim 5, It is characterized in that：Described device also includes drive control assembly, and described drive control assembly includes host computer, is used for detecting freedom With the grating scale (14) of moving cell and the change of servo servo-actuated cell position, the Circular gratings for detecting cam axle information, Host computer and the read head of grating scale, the read head of Circular gratings and for driving servo with servomotor (9) phase of moving cell Even.

8. a kind of inspection of camshaft complexity molded line lift full-automatic servo follow-up tracing precision sweep detection means as claimed in claim 5 Survey method it is characterised in that：Comprise the following steps：

Servo is with the gauge head (12) on moving cell with servo moving close to and contacting camshaft with moving cell；Then pass through precision Rotary axis system (4) makes described cam axle, in the rotation process of camshaft, according to freedom with moving cell with camshaft lift The change in location real-time adjustment servo of change, with the position of moving cell, makes freely keeping gauge head (12) and camshaft with moving cell All the time it is in the centre position of stroke on the premise of contact；Meanwhile, synchronous acquisition freely with moving cell and servo with moving cell Displacement information and camshaft rotation information, freely believing synchronous acquisition with the displacement of moving cell with servo with moving cell Breath superposition, the rotation information then in conjunction with the camshaft of synchronous acquisition obtains the outline data of camshaft.