WO2022063748A1

WO2022063748A1 - Improved system for punching holes in a profile with high-throughput and its method

Info

Publication number: WO2022063748A1
Application number: PCT/EP2021/075876
Authority: WO
Inventors: Luc De Sutter
Original assignee: Soenen Technology Nv
Priority date: 2020-09-22
Filing date: 2021-09-21
Publication date: 2022-03-31
Also published as: BE1028626B1; CN215845153U; BE1028626A1

Abstract

The current invention relates to a system for punching of holes in a profile with high-throughput comprising a clamp unit, comprising a clamp, slideable in a first direction, a punch unit for punching holes in the profile, wherein a punch unit comprises a punch and a piston, wherein the piston is configured to move the punch in a stroke direction, transverse to the first direction, over a stroke length, wherein the system comprises a control unit configured to adjust the stroke length of the punch. The inventions also relates to a method for punching of holes in a profile with high-throughput.

Description

IMPROVED SYSTEM FOR PUNCHING HOLES IN A PROFILE WITH HIGH- THROUGHPUT AND ITS METHOD

FIELD OF THE INVENTION

The present invention relates to a system for punching of holes in a profile with high-throughput.

In a second aspect, the present invention also relates to a method for punching of holes in a profile with high-throughput.

In another aspect, the present invention also relates to a use for punching holes in web and flanges of a U-profile for a truck or trailer chassis.

BACKGROUND

Punch lines for punching holes in elongated profiles are known from the state of the art. A punch line comprises at least one punch unit and at least a feeding device for displacing the profile along the punch line to and through the punch unit. The feeding device is driven by a servomotor through a transmission.

Punch lines are for instance used for producing beams of a truck or trailer chassis. The beams are made from U-profiles. The chassis of the truck or trailer consists mainly of two U-profiles in the longitudinal direction of the truck or trailer. The opening of the U-profiles are facing each other. The U-profiles are connected with several cross-beams. Connections are with bolts or rivets. Holes have to be foreseen in the U-profiles for said connections.

On the truck or trailer chassis, different parts and accessories have to be fixed. Examples of parts and accessories are the engine, wheel units, fuel tank,... During the assembly of the truck or the trailer all these parts and accessories are fixed to the chassis with bolts or rivets. Again holes in the U-profiles are required. In the particular case of a heavy truck, often a reinforcement U-profile is inserted inside the beams and has to be connected to said beams with bolts and rivets.

Many holes are to be punched in the U-profiles. Many of these holes are positioned in the web of the U-profiles. Also a reasonable amount of holes are to be punched in the flanges of the U-profiles. These holes can have different diameters. The number of holes in a U-profile for a truck or trailer can vary between 150 and 900.

For a high-throughput in producing profiles it is essential to be able to punch holes at high pace. A punch line according to the state of the art is not suited for high- throughput punching holes in a profile. Firstly a punch unit of a punch line according to the state of the art has a fixed mechanical construction, resulting in an identical time for punching a hole, independent of the size of the profile and its type of material. Optimization of the time required for punching a hole is not possible. Secondly, every hole requires repositioning of the profile by the feeding device until the position of the profile in the punch unit corresponds with the desired position of the hole. This lowers the throughput.

Known punch lines are described in US 5 435 216, JP Hll 226664, US 5 027 631, US 3 667 333, CN 111 360 141 and US 1 775 359.

The present invention aims to resolve at least some of the problems and disadvantages mentioned above.

SUMMARY OF THE INVENTION

The present invention and embodiments thereof serve to provide a solution to one or more of above-mentioned disadvantages. To this end, the present invention relates to a system for punching holes in a profile with high-throughput according to claim 1.

The system comprises a clamp unit, comprising a clamp, slideable in a first direction, and a punch unit for punching holes in the profile. The punch unit comprises a punch and a piston, wherein the piston is configured to move the punch in a stroke direction, transverse to the first direction, over a stroke length. The system comprises a control unit configured to adjust the stroke length of the punch. This is beneficial because it is possible to reduce the stroke length when punching holes in a thin profile and to increase the stroke length when punching holes in a thick profile. No time is lost by unnecessary long stroke lengths because the punch is positioned too far from the profile or because the punch still moves while the profile is already punched through, resulting in a shorter punch time for a hole and a high throughput.

Preferred embodiments of the device are shown in any of the claims 2 to 8. A specific preferred embodiment relates to an invention according to claim 3. The punch unit comprises a proportional valve, configured to control the speed of the punch. This is beneficial because the speed of the punch can be adjusted in function of the thickness of the profile and the strength of the material. In a thin and/or soft material it is possible to punch holes with a punch at high speed without damaging the punch. In a thicker material, a high speed of the punch will result in high wear. By adapting the speed of the punch, an optimization of the throughput can be obtained without excessive wear of punches.

In a second aspect, the present invention relates to a method according to claim 9. More particular, the method as described herein provides that a profile is clamped in a clamp of a clamp unit, displaced in a punch unit by sliding the clamp in a first direction, and punching at least one hole in the profile by the punch unit, wherein the punch unit comprises a punch and a piston, wherein the piston is configured to move the punch in a stroke direction, transverse to the first direction, over a stroke length and wherein the stroke length of the punch is controlled by a control unit. This is beneficial because no time is lost by unnecessary long stroke lengths because the punch is positioned too far from the profile or because the punch still moves while the profile is already punched through, resulting in a high throughput.

Preferred embodiments of the method are shown in any of the claims 10 to 14.

In a third aspect the present invention relates to a use according to claim 15. The use as described herein provides an advantageous effect that holes can be punched with a high throughput in web and flanges of a U-profile of a truck or trailer chassis.

DESCRIPTION OF FIGURES

Figure 1 shows a schematic overview of a punch line comprising a system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

As used herein, the following terms have the following meanings:

"A", "an", and "the" as used herein refers to both singular and plural referents unless the context clearly dictates otherwise. By way of example, "a compartment" refers to one or more than one compartment.

"Comprise", "comprising", and "comprises" and "comprised of" as used herein are synonymous with "include", "including", "includes" or "contain", "containing", "contains" and are inclusive or open-ended terms that specifies the presence of what follows e.g. component and do not exclude or preclude the presence of additional, non-recited components, features, element, members, steps, known in the art or disclosed therein.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order, unless specified. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

The recitation of numerical ranges by endpoints includes all numbers and fractions subsumed within that range, as well as the recited endpoints.

Whereas the terms "one or more" or "at least one", such as one or more or at least one member(s) of a group of members, is clear per se, by means of further exemplification, the term encompasses inter alia a reference to any one of said members, or to any two or more of said members, such as, e.g., any >3, >4, >5, >6 or >7 etc. of said members, and up to all said members. Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

In the context of this document a profile extends into a longitudinal direction. A profile has a transverse cross-section, mostly invariant between its two end portions. A profile comprises a base. The base is a central substantially flat surface of the profile. Generally the base is the biggest surface of the profile. The profile can comprise additional walls at sides of the base or on the surface of the base.

In the context of this document a U-profile is a profile with a cross-section in the shape of a letter U. The U-profile comprises a base, called web, and at each side of the base a side wall, called flange. The flanges are substantially perpendicular to the base. The flanges of the U-profile extend in the same direction.

In the context of this document a L-profile is a profile with a cross-section in the shape of a letter L. The L-profile comprises a first wall and a second wall, perpendicular to each other. The wall having the biggest surface is the base of the profile.

In the context of this document, camber is a deviation wherein the profile is not perfectly straight, but bends along the longitudinal direction in a plane formed by the base of the profile. In case of a U-profile the base is the web, so the profile bends in a plane defined by the web.

In the context of this document, bow is a deviation wherein the profile is not perfectly straight, but bends along the longitudinal direction in a plane, perpendicular to the plane formed by the base side of the profile. In case of a U- profile the base is the web, so the profile bends in a plane perpendicular to the web.

In the context of this document, throughput is expressed in the number of holes per minute that can be punched in a profile.

In a first aspect, the invention relates to a system for punching of holes in a profile with high-throughput.

In a preferred embodiment the system comprises a clamp unit and a punch unit for punching holes in the profile. The system is placed on a floor surface. The clamp unit comprises a clamp and a support structure. The clamp of the clamp unit is positioned on the support structure. The support structure comprises a longitudinal axis, wherein said longitudinal axis is substantially parallel with the floor surface. This longitudinal axis will be denoted as X-axis in the context of this document. An axis perpendicular to the X-axis and parallel with the floor surface will be denoted as Y-axis and an axis perpendicular to the plane formed by the X- axis and Y-Axis will be denoted with Z-axis in the context of this document. The support structure comprises a first and a second end. The punch unit is positioned at the second end of the support structure. The clamp of the clamp unit is slideable in a first direction. This first direction corresponds with the direction of the X-axis. The clamp is configured for displacing the profile along the X-axis in the punch unit, wherein the profile extends into a longitudinal direction and wherein said longitudinal direction is parallel with the X-axis. This enables the system to punch holes in the profile at different positions along said profile.

The punch unit comprises a punch and a piston. The punch is attached to a first die shoe. A second die shoe comprises a complementary hole for the punch. The punch unit comprises a passage for profiles in between the punch attached to the first die shoe and the second die shoe. The piston is configured to move the punch in a stroke direction, transverse to the first direction, from a first position at a distance of the second die shoe to a second position. In the second position the punch is positioned at least partly in the complementary hole in the second die shoe. The piston is configured to move the punch over a stroke length. The stroke length is the distance travelled by a punch along the stroke direction from the first position to the second position. The punch unit can punch a hole in a profile positioned in the passage by moving the punch from the first to the second position. The punch is moved by the piston by moving directly the punch or alternatively by moving the first die shoe to which the punch is attached.

Preferably the stroke direction corresponds with the Y-axis or the Z-axis. When the stroke direction corresponds to the Z-axis, the first die shoe and the punch are preferably positioned at an upper side of the passage and the second die shoe at an opposite lower side of the passage. The first die shoe is in this case also called upper die shoe and the second die shoe lower die shoe. This positioning is advantageous for automatically removing material punched out the profile by the punch unit by means of gravity.

The system comprises a control unit configured to adjust the stroke length of the punch. Preferably the control unit adjusts the stroke length based on the thickness of the profile. The thickness of the profile can be entered by a user. The control unit is a centrally placed control unit, communicating with the punch unit over a network. Alternatively the control unit is comprised in the punch unit. Preferably the stroke length is adjustable by changing the first position of the punch. Alternatively the stroke length is adjustable by changing the second position. Alternatively the stroke length is adjustable by changing the first and second position of the punch. An adjustable stroke length is advantageous for adjusting the time required for punching a hole in a profile, depending on the thickness of the profile, compared to a fixed stroke length suitable for all intended profile thicknesses according to a system of the prior art. The latter system results in many cases, when the thickness of the profile is smaller than the maximum intended profile thickness, in unnecessary long stroke lengths because the first position is at an unnecessary distance to the profile, what reduces the throughput of the system or because the punch is still moved in the stroke direction while the profile is already punched through. With a system according to the current invention the average time for punching a hole is less because the stroke length can be adjusted to for instance the thickness of the profile, which results in a higher throughput of the system.

It is for a person of ordinary skill in the art clear that the system can comprises more than one punch unit. If the system comprises more than one punch unit, the punch units and the clamp unit are placed in line along the first direction on the floor surface. In an embodiment the stroke length is minimal 15 mm, preferably minimal 17 mm, more preferably minimal 19 mm and even more preferably minimal 20 mm. Preferably the stroke length is such that a punch enters at least 1 mm in the second die shoe while punching a hole, more preferably at least 2 mm, even more preferably at least 3 mm. If the punch enters less than 1 mm in the second die shoe, it is possible that a hole is punched but that scrap is not discharged through the die and gets stuck in the punched hole. A higher minimum stroke length is beneficial for allowing some camber and/or bow. With a higher minimum stroke length the punch can be positioned in the first position at a bigger distance to the second die shoe, creating a bigger passage for the profile. For instance, a stroke length of minimum 20 mm allows for punching a hole in a profile with a thickness of 12 mm and a bow of maximum 8 mm over its length.

In an embodiment the stroke length is maximal 35 mm, preferably maximal 33 mm, more preferably maximal 31 mm and even more preferably maximal 30 mm. A maximum stroke length of 30 mm is beneficial to accelerate the punch sufficiently so that it hits a profile, with a thickness of 12 mm and a camber of 8 mm over its length, at the maximum speed of the punch.

A person of ordinary skill in the art will understand that depending on the thickness of the profile and the present camber and bow, the stroke length can be adjusted. For instance, for a profile with a thickness of 12 mm and a bow of maximum 8 mm, a stroke length of 25 mm is selected. The time for punching a hole is in this case 0.300 seconds. When punching holes in a profile with a thickness of 4 mm and similar bow, the stroke length can be reduced to 17 mm. Assuming a constant and equal speed as in the case of a profile with a thickness of 12 mm, the time for punching a hole is now 0.204 seconds. This is a reduction in time of 32%.

In an embodiment the piston is air driven. Alternatively the piston is oil driven.

In an embodiment the punch unit comprises a linear encoder, configured to measure a displacement by the piston in the stroke direction. The displacement by the piston is the displacement of a punch or alternatively the displacement of a fist die shoe to which the punch is attached. The linear encoder extends in the stroke direction. The linear encoder has a minimal measurement accuracy in the stroke direction of ± 2 mm, preferably ± 1 mm, more preferably ± 0.5 mm and even more preferably ± 0.25 mm. A linear encoder is advantageous for accurately positioning the punch of the punch unit in reference to the second die shoe or vice versa. In this way it is possible to adjust correctly the stroke length.

In an embodiment the linear encoder has a measuring range of least 220 mm, preferably at least 230 mm, more preferably at least 240 mm, even more preferably at least 250 mm. The measuring range is defined as the distance between a lowest and highest possible output of the linear encoder. Such a measuring range is advantageous for adjusting the stroke length according to previously described embodiments of the current invention. Such measuring range is especially advantageous when the first die shoe is moveable starting from the first position in the stroke direction and away from the second position over a distance of at least 180 mm, preferably at least 185 mm and more preferably at least 190 mm, for instance to position the first die shoe with the attached punch further away from the second die shoe to replace a broken or worn punch. Due to the minimum measuring range of the linear encoder, it is possible to position the punch after the replacement accurately back at the first position, obtaining the correct stroke length.

In an embodiment the punch unit comprises a sensor, configured to measure a distance between a profile and the punch of the punch unit. This is advantageous because the stroke length can be adjusted automatically instead of requiring manual input by a user of the thickness of the profile. This is especially advantageous in case the profile has camber or bow. The distance of the profile to the punch can vary over the length of the profile depending on the amount of camber or bow. Based on the measurements of the sensor, the stroke length can be continuously adjusted to obtain an optimized stroke length.

In a further embodiment the sensor is a laser. Alternative the sensor is a measuring wheel or measuring pin coupled to a linear encoder.

In a preferred embodiment, the punch unit comprises a proportional valve, configured to control the speed of the punch. The proportional valve comprises an output, connected to the piston of the punch unit and an input. The proportional valve is configured such that a change in flow or pressure of air or oil at the output of the proportional valve changes in the same ration as a value at the input of the proportional valve. The input value is an analogue voltage or electrical current. The input value is used to control the speed of the punch. This is advantageous because the speed of the punch can be adjusted in function of the thickness of the profile and the strength of a material of which the profile consists. In a thin profile and/or soft material it is possible to punch holes with a high speed of the punch. A high speed corresponds with a high throughput. However, in a thick profile or in a profile consisting of a strong material, a high speed will result in heating of the punch and excessive wear and/or damage. A proportional valve allows optimization of the speed of punches and consequently the throughput without excessive wear of punches and/or damage to punches.

In an embodiment the punch unit comprises a manometer, configured to measure a pressure in the piston. The manometer is advantageous for measuring shear strength of a material of a profile when the thickness of the material and the diameter of the hole are known. As previously described in an embodiment the strength, more particularly the shear strength, influences the speed with which a punch can be driven through a profile. The manometer is additionally advantageous to control the speed of the punch. The pressure in the piston will start increasing when the punch hits the material of the profile and will reach a maximum just before the material of the profile starts shearing and breaking. When punching the hole is completed, the pressure in the piston will reach again a minimum. The speed of the punch can be gradually decreased when reaching the completion of punching the hole to reduce stress in the punch when the punch reaches the second position. This increases the lifetime of the punch.

In an embodiment the system comprises an additional punch unit. The additional punch unit is placed on the floor surface in line along the first direction with the clamp unit and the punch unit. The additional punch unit can be placed between the clamp unit and the punch unit or the punch unit can be placed between the clamp unit and the additional punch unit. The additional punch unit comprises a support structure. The support structure comprises a longitudinal axis, wherein said longitudinal axis is parallel with the floor surface. The punch unit comprises a piston, a punch unit, a first die shoe and a second die shoe, with similar function as described in an previous embodiment of a punch unit. The additional punch unit is displaceable in the first direction. For that purpose the piston, punch unit, first die shoe and second die shoe are slideable along the longitudinal axis of said support structure. This is advantageous because while the clamp unit is displacing the profile in the first direction in the punch unit so that the profile is correctly positioned in the punch unit for punching a first hole in the profile, the additional punch unit can be displaced simultaneously in the first direction so that the additional punch unit is correctly positioned for punching a second hole in the profile, without requiring an additional displacement by the clamp unit. This saves time because it is not required to displace the profile after punching the first hole for punching the second hole with the additional punch unit.

It is for a person of ordinary skill in the art clear that the system can comprises more than one additional punch unit.

In a further embodiment the additional punch unit is displaceable in the first direction over a distance of at least 200 mm and at most 600 mm. A displacement within this range is sufficiently large to allow in most cases to punch a second hole with the additional punch unit without displacing a profile with the clamp unit. The additional punch unit is displaceable in the first direction with a speed of at least 10 m/min and at most 50 m/min. A speed within this range allows to reposition the additional punch unit within the same time slot as required for repositioning the profile with the clamp unit.

The additional punch unit is displaceable over a distance of preferably at least 250 mm, more preferably at least 300 mm and even more preferably at least 350 mm.

The additional punch unit is displaceable over a distance of preferably at most 550 mm, more preferably at most 500 mm and even more preferably at most 450 mm.

The additional punch unit is displaceable in the first direction with a speed of preferably at least 15 m/min, more preferably at least 20 m/min and even more preferably at least 25 m/min.

The additional punch unit is displaceable in the first direction with a speed of preferably at most 45 m/min, more preferably at most 40 m/min and even more preferably at most 35 m/min.

In an embodiment an additional punch unit comprises a drive. The drive is configured for displacing the additional punch unit in the first direction. The drive comprises a servomotor. The servomotor is preferably a permanent magnet servomotor. A rotational movement of the servomotor is translated in a linear movement by a transmission. The transmission comprises a belt, gear with gear rack, a ball screw spindle or another suitable means for translating rotational motion of the servomotor to linear motion of the additional punch unit. Preferably the transmission comprises a ball screw spindle. A ball screw is advantageous because it introduces little friction and because it can be assembled with high precision, allowing accurate positioning of the additional punch unit. The positioning of the additional punch unit in the first direction has a minimal accuracy in the first direction of ± 0.4 mm, preferably ± 0.3 mm, more preferably ± 0.2 mm and even more preferably ± 0.1 mm.

In an embodiment the additional punch unit comprises a linear encoder. The linear encoder is configured for measuring a displacement of the additional punch unit in the first direction. The linear encoder extends in the first direction, along the X- axis. The linear encoder is preferably attached to the support structure of the additional punch unit. The linear encoder has a minimal measurement accuracy along the X-axis of ± 0.04 mm, preferably ± 0.03 mm, more preferably ± 0.02 mm and even more preferably ± 0.01 mm. The linear encoder has a measuring range of least 200 mm, preferably at least 250 mm, more preferably at least 300 mm, even more preferably at least 350 mm. The linear encoder has a measuring range of most 600 mm, preferably at most 550 mm, more preferably at most 500 mm, even more preferably at most 450 mm. These ranges corresponds with a possible displacement of the additional punch unit as described in a previous embodiment. The measuring range is defined as the distance between a lowest and highest possible output of the linear encoder. A linear encoder is advantageous for accurately positioning the additional punch unit in reference to the punch unit and consequently accurately punching a second hole in the profile without an additional displacement of the profile with the clamp unit. The linear encoder measures directly the displacement of the additional punch unit in the first direction. Errors in the displacement in the first direction of the additional punch unit, caused by tolerances in mechanical components, are included in the measurement. Said errors can therefore be corrected by adjusting the displacement of the additional punch unit.

In an embodiment the punch unit and the additional punch unit are configured to punch holes simultaneously. This is advantageous because a first hole can be punched by the punch unit and a second hole can be punched by the additional punch unit, without having to wait for the punch unit to finish punching the first hole and without having to displace the profile with the clamp unit. This results in an additional time saving. The inventors surprisingly remarked that punching a first and a second hole simultaneously also results in an improved accuracy of the position of the first and second hole in the first direction, because vibrations caused by punching the first hole, that could result in a small shift of the profile, cannot influence the position of the second hole as it is punched at the same time as the first hole.

In an embodiment a punch unit comprises a first die shoe and a second die shoe, wherein the first die shoe comprises at least two punches, and wherein the first die shoe and the second die shoe are configured to punch at least two holes simultaneously, wherein the at least two holes have a fixed distance between them in the first direction and/or in a direction transverse to the first direction. The first die shoe comprises preferably at least three punches, more preferably at least four punches, and even more preferably at least five punches. The first die shoe and second die shoe are configured to punch preferably at least three holes, more preferably at least four holes and even more preferably at least five holes. It is for a person of ordinary skill in the art clear that the number of holes that can be punched simultaneously by a punch unit depends on the maximum pressure that can be developed by the piston of the punch unit or additional punch unit, a diameter of the punches and the thickness of the profile. This embodiment is advantageous if a profile comprises sections with multiple holes with a limited and fixed distance between them. The holes in such a section are positioned in a grid. It is in this case not required to have multiple punch units and/or additional punch units to punch these holes simultaneously. This simplifies the system. The drawback is that this embodiment cannot be used to punch holes simultaneously in a profile when the distance between holes varies continuously. In that case a system with a punch unit and an additional punch unit as described in a previous embodiment is more advantageous. It is for a person of ordinary skill in the art clear that this embodiment can be combined with an additional punch unit and that an additional punch unit can also be according to this embodiment.

In a further embodiment, a punch unit comprises a selection control, configured for selecting one or at least two punches of the first die shoe, for punching one or at least two holes simultaneously. The selection control selects one or at least two punches that are moved by the piston through the profile. The selected punches are moved directly by the piston or alternatively the selected punches are moved together with the first die shoe. The non-selected punches attached to the first die shoe remain stationary in the first position. This is advantageous for increasing the flexibility of the system and increasing the throughput of the system because when for instance the distance between the holes in a section changes, other punches can be selected that are positioned at another distance from each other. Although the distance changed, the holes can still be punched simultaneously. Another gain in flexibility is that when the diameter of the holes changes, punches with another diameter available in the first die shoe and at a correct distance between them, can be selected to punch the holes simultaneously.

In an embodiment the system comprises at least two clamps units. Said clamp units are similar to a clamp unit described in a previous embodiment. A first support structure of a first clamp unit, supporting a first clamp, is identical to the support structure described in a previous embodiment. A second support structure of a second clamp unit, supporting a second clamp, is positioned in line, along its longitudinal axis, with the first support structure. The at least two clamps are slideable in the first direction. At least one punch unit is positioned in between the at least two clamp units. The at least one punch unit is positioned between the second end of the first support structure and the first end of the second support structure. The first clamp is configured for displacing the profile along the X-axis in the at least one punch unit, wherein the profile extends into a longitudinal direction and wherein said longitudinal direction is parallel with the X-axis. The second clamp is configured for displacing the profile along the X-axis out the at least one punch unit.

A system according the current embodiment is advantageous for creating a continuous punch line, wherein profiles are fed by the first clamp unit and removed by the second clamp unit. This increases the throughput of the system. The embodiment is also advantageous when it is required to punch holes over substantially the whole length of the profile. In that case it is not possible to clamp the profile with the first clamp on a position not requiring punching holes. By taking over the profile with the second clamp, the first clamp can be released and holes can be punched in the profile on the position previously covered by the first clamp. This avoids that the profile needs to be turned around by an operator and has to be clamped again by the first clamp, to punch the holes on the position previously covered by the first clamp.

It is for a person of ordinary skill in the art clear that more than one punch unit and at least one additional punch unit can be positioned between the first and second clamp unit. It is for a person of ordinary skill in the art also clear when multiple punch units are positioned between the first and second clamp unit, said multiple punch units can extend along the X-axis over a length longer than the length of a profile, requiring one or more additional clamp units in between the first and second clamp unit. Said one or more additional clamp units are similar to clamp units described in the current and previous embodiments. The support structures of said one or more additional clamp units are positioned in line, along their longitudinal axis, with the first support structure. The clamps of said one or more additional clamp units are slideable in a first direction. Multiple clamp units and punch units are also advantageous for processing multiple profiles simultaneously, in which a first profile is clamped by a first clamp unit and punched by a first punch unit and simultaneously a second profile is clamped by a second clamp unit and punched by a second punch unit, resulting in a further increased throughput.

In a second aspect, the invention relates to a method for punching of holes in a profile with high-throughput.

In a preferred embodiment, the method comprises the steps of clamping a profile in a clamp of a clamp unit, displacing the profile by sliding the clamp in a first direction in a punch unit and punching at least one hole in the profile by the punch unit. The punch unit comprises a punch and a piston. The punch is attached to a first die shoe. A second die shoe comprises a complementary hole for the punch. The punch unit comprises a passage for profiles in between the punch attached to the first die shoe and the second die shoe. The piston moves the punch in a stroke direction, transverse to the first direction, from a first position at a distance of the second die shoe to a second position. In the second position the punch is positioned at least partly in the complementary hole in the second die shoe. The piston moves the punch over a stroke length. The stroke length is the distance travelled by a punch along the stroke direction from the first position to the second position. The punch unit punches a hole in a profile positioned in the passage by moving the punch from the first to the second position while a profile is positioned in the punch unit between the punch and the second die shoe. The stroke length of the punch is controlled by a control unit. The control unit adjusts the stroke length, preferably depending on the thickness of the profile. The stroke length is adjusted by changing the first position of the punch. Alternatively the stroke length is adjusted by changing the second position of the punch. Alternatively the stroke length is adjusted by changing the first and second position of the punch.

Controlling the stroke length of the punch is advantageous because no time is lost by unnecessary long stroke lengths because the punch is positioned too far from the profile or because the punch is still being moved by the piston while the profile is already punched through. With a method according to the current invention the average time for punching a hole is less because the stroke length is controlled and adjusted to for instance the thickness of the profile, which results in a higher throughput of the system.

In an embodiment the method comprises the additional step of entering the thickness of the profile in the control unit. This is beneficial to adjust the stroke length by the control unit.

In an embodiment the method comprises the additional step of continuously measuring the thickness of the profile. The thickness is measured with a sensor. The thickness of the profile is measured over the whole length of the profile. This is advantageous because the stroke length can be adjusted automatically instead of requiring manual input by a user of the thickness of the profile. This is especially advantageous in case the profile has camber or bow. The distance of the profile to the punch can vary over the length of the profile depending on the amount of camber or bow. Based on the measurements of the sensor, the stroke length can be continuously adjusted to obtain an optimized stroke length.

In an embodiment a displacement by the piston in the stroke direction is measured during punching a hole. Measuring the displacement by the piston is advantageous for accurately executing the piston displacement from the first position to the second position. This is especially advantageous for controlling the speed of the punch with which it is displaced from the first to the second position. The advantages of controlling the speed of the punch are discussed in previously described embodiments of a system according to the current invention.

In an embodiment the pressure in the piston is measured during punching a hole. The pressure is measured preferably with a manometer or pressure sensor. Measuring the pressure in the piston is advantageous for measuring shear strength of a material of a profile when the thickness of the material and the diameter of the hole are known. The strength of the material, more particularly the shear strength, influences the speed with which a punch can be driven through a profile.

In a further embodiment the speed of the punch is automatically adjusted in function of the measured pressure in the piston. The pressure in the piston will start increasing when the punch hits the material of the profile and will reach a maximum just before the material of the profile starts shearing and breaking. When punching the hole is completed, the pressure in the piston will reach again a minimum. The speed of the punch can be gradually decreased when reaching the completion of punching the hole to reduce stress in the punch when the punch reaches the second position. This increases the lifetime of the punch while maintaining a high throughput.

In an embodiment the method comprises the additional step of displacing an additional punch unit in the first direction. The additional punch unit can be placed between the clamp unit and the punch unit or the punch unit can be placed between the clamp unit and the additional punch unit. The additional punch unit is placed in line with the punch unit and the clamp unit. The additional punch is displaceable in the first direction. This is advantageous because while the clamp unit is displacing the profile in the first direction in the punch unit so that the profile is correctly positioned in the punch unit for punching a first hole in the profile, the additional punch unit can be displaced simultaneously in the first direction so that the additional punch unit correctly positioned for punching a second hole in the profile, without requiring an additional displacement by the clamp unit. This saves time because it is not required to displace the profile after punching the first hole for punching the second hole with the additional punch unit.

In a further embodiment, the punch unit and the additional punch unit punch holes simultaneously. This is advantageous because a first hole can be punched by the punch unit and a second hole can be punched by the additional punch unit, without having to wait for the punch unit to finish punching the first hole and without having to displace the profile with the clamp unit. This results in an additional time saving. The inventors surprisingly remarked that punching a first and a second hole simultaneously also results in an improved accuracy of the position of the first and second hole in the first direction, because vibrations caused by punching the first hole, that could result in a small shift of the profile, cannot influence the position of the second hole as it is punched at the same time as the first hole.

In an embodiment, the punch unit punches at least two holes simultaneously, wherein the at least two holes have a fixed distance between them in the first direction and/or in a direction transverse to the first direction. The punch unit comprises a first die shoe and a second die shoe. The first die shoe comprises at least two punches. The first die shoe and the second die shoe are configured to punch at least two holes simultaneously. This embodiment is advantageous if a profile comprises sections with multiple holes with a limited and fixed distance between them. It is in this case not required to have multiple punch units and/or additional punch units to punch these holes simultaneously. This embodiment cannot be used to punch holes simultaneously in a profile when the distance between holes varies continuously. It is for a person of ordinary skill in the art clear that this embodiment of the method can be combined with a method including the use of an additional punch unit as previously described and that an additional punch unit can also be used to punch at least two holes having a fixed distance between them in the first direction and/or in a direction transverse to the first direction according to this embodiment of the method.

In a third aspect, the invention relates to use of a system according to the first aspect or a method according to the second aspect for punching holes in web and flanges of a U-profile for a truck or trailer chassis.

This use provides an advantageous effect that holes can be punched with a high throughput in web and flanges of a U-profile of a truck or trailer chassis. This is important as U-profiles of a truck or trailer chassis can easily comprise 150 up to 900 holes. Even a small reduction in time required for punching one hole in a beam will result in a higher throughput of U-profiles.

The use of a system according to the first aspect or a method according to the second aspect allows processing U-profiles for truck or trailers with a length of at least 4 m up to 12 m. The system allows use of a U-profile which can have a camber of at least 1 mm per 1000 mm of length with a maximum aggregated camber of 5 mm on a total length of 12 000 mm, preferably a maximum aggregated camber of 6 mm, more preferably a maximum aggregated camber of 7 mm and even more preferably a maximum aggregated camber of 8 mm. The system allows use of a U-profile which can have a bow of at least 3 mm per 2000 mm of length with a maximum aggregated bow of 8 mm on a total length of 12 000 mm, preferably a maximum aggregated bow of 9 mm, more preferably a maximum aggregated bow of 10 mm and even more preferably a maximum aggregated bow of 11 mm. The number of processed U-profiles can be up to 325 U-profiles per day for a working day of 21.5 hours, wherein the U-profiles comprise 270 holes, wherein 50% of the holes can be punched simultaneously, wherein a punch unit and an additional punch unit are used for punching holes in the web of the U-profile and wherein 90% of the holes are in the web. The number of processed U-profiles can be up to 401 U-profiles per day for a working day of 21.5 hours, wherein the U-profiles comprise 270 holes, wherein 50% of the holes can be punched simultaneously, wherein a punch unit and an additional punch unit are used for punching holes in the web of the U-profile, wherein 90% of the holes are in the web and wherein 50% of these holes are punched simultaneously in groups of at least two holes (in grid) by the punch unit.

It is clear that the method according to the invention, and its applications, are not limited to the presented examples.

It is clear for a person of ordinary skill in the art that a system according to the first aspect is preferably configured for executing a method according to the second aspect and that a method according to the second aspect can be executed using a system according to the first aspect. Every characteristic, described in this document, above as below, can be applicable to each of the three aspects of the current invention.

The invention is further described by the following non-limiting figure which further illustrates the invention, and is not intended to, nor should it be interpreted to, limit the scope of the invention.

DESCRIPTION OF FIGURES

Figure 1 shows a schematic overview of a punch line comprising a system according to an embodiment of the present invention.

The punch line depicted in Figure 1 is suitable for punching U-profiles for trucks or trailers. The punch line is placed on a floor surface (20). The punch line comprises a clamp unit (1). The clamp unit (1) extends along a first direction, corresponding to the direction of the X-axis. Profiles (3) extend in a longitudinal direction. The profiles (3) are U-profiles. The profiles (3) are processed in the punch line, whereby the longitudinal direction of the profiles (3) is parallel with the X-axis. The clamp unit (1) comprises a clamp (2). The clamp (2) is slideable along the direction of the X-axis. The clamp (2) is configured to displace a profile (3) in a punch unit (4). Punch unit (4) is configured for punching holes in the web of a profile (3). The punch unit (4) comprises a piston (6), a first die shoe (8) and a second die shoe (10). In this case the first die shoe (8) is also called upper die shoe and the second die shoe (10) the lower die shoe. Three punches (9) are attached to the first die shoe (8). The second die shoe (10) comprises complementary holes to receive the punches (9) attached to the first die shoe. The punch unit (4) comprises a piston (6), configured to move at least one punch (9) in a stroke direction, transverse to the first direction over a stroke length, by moving the first die shoe (8). The stroke direction is parallel with the Z-axis. The at least one punch (9) is moved by the piston (6) from a first position at a distance from the second die shoe (10) through the web of a profile (3) to a second position wherein the punch (9) enters at least partly in the complementary hole of the second die shoe (10). The punch unit (4) comprises a linear encoder (7) attached to the piston (6) and the first die shoe (8) to measure displacement by the piston (6) in the stroke direction. The first die shoe (8) is configured to selectively use one, two or even three punches (9) to punch respectively one, two or three holes simultaneously in a profile (3). This is advantageous to obtain a high throughput when a profile (3) contains one or more sections in which multiple holes have to be punched, wherein the holes have a fixed distance between them in the first direction and/or in a direction transverse to the first direction and wherein the distance corresponds to a distance between punches (9) of punch unit

(4). When a punch (9) of the first die shoe (8) is selected, the selected punch (9) moves together with the first die shoe (8) in the stroke direction. Punch unit (4) is followed by an additional punch unit (5). The punch unit (5) is similar to punch unit (4). Additional punch unit (5) is added due to the high number of holes that have to be punched in the web of profile (3) and to increase the throughput. Additional punch unit (5) is slideable in the first direction, parallel with the X-axis. Additional punch unit (5) comprises a support structure (11), extending in a longitudinal direction, parallel with the X-axis and parallel with the floor surface (20). The additional punch unit (5) comprises a linear encoder (12), configured for measuring a displacement of the additional punch using in the first direction. Displacing the additional punch unit (5) in the first direction enables to punch a hole in a profile (3) simultaneously with punch unit (4) without displacing the profile (3) with the clamp (2) or clamp (14). When exiting additional punch unit

(5), a profile (3) is taken over by clamp (14) of the clamp unit (13). The clamp (14) clamps a profile (3) while the clamp (2) is still clamping profile (3) and while clamp (2) is stationary. Clamp (14) is at that moment also stationary. Clamp (2) releases profile (3) when clamp (14) successfully clamped profile (3). Clamp (14) is displacing a profile (3) into punch unit (15). Punch unit (15) is configured for punches holes in a first flange of a profile (3). Punch unit (15) is similar to punch unit (4), with the important difference that the punch unit is configured to punch holes in a direction parallel to the Y-axis. Punch unit (15) is followed by punch unit (16). Punch unit (16) is similar to punch unit (4). Punch unit (16) can punch holes with a different diameter than punch unit (4). Punch unit (16) is followed by punch unit (17). Punch unit (17) is similar to punch unit (15). Punch unit (17) is added to punch holes in a second flange of profile (3). When exiting punch unit (17), profile

(3) is taken over by clamp (19) of clamp unit (18). Taking over is happening similarly as described before.

Claims

22 CLAIMS

1. System for punching of holes in a profile with high-throughput comprising a clamp unit, comprising a clamp, slideable in a first direction, a punch unit for punching holes in the profile, wherein a punch unit comprises a punch and a piston, wherein the piston is configured to move the punch in a stroke direction, transverse to the first direction, over a stroke length, characterized in that, the system comprises a control unit configured to adjust the stroke length of the punch.

2. System according to claim 1, wherein the punch unit comprises a linear encoder, configured to measure a displacement by the piston in the stroke direction.

3. System according to claim 1 or 2, wherein the punch unit comprises a proportional valve, configured to control the speed of the punch.

4. System according to any of the previous claims 1-3, wherein the punch unit comprises a manometer, configured to measure a pressure in the piston.

5. System according to any of the previous claims 1-4, wherein the system comprises an additional punch unit, displaceable in the first direction.

6. System according to claim 5, wherein the additional punch unit comprises a linear encoder, configured for measuring a displacement of the additional punch unit in the first direction.

7. System according to any of the previous claims 5-6, wherein the punch unit and the additional punch unit are configured to punch holes simultaneously.

8. System according to any of the previous claims 1-7, wherein a punch unit comprises a first die shoe and a second die shoe, wherein the first die shoe comprises at least two punches, and wherein the first die shoe and the second die shoe are configured to punch at least two holes simultaneously, wherein the at least two holes have a fixed distance between them in the first direction and/or in a direction transverse to the first direction.

9. Method for punching of holes in a profile with high-throughput comprising clamping a profile in a clamp of a clamp unit; displacing the profile in a punch unit by sliding the clamp in a first direction, wherein a punch unit comprises a punch and a piston, wherein the piston is configured to move the punch in a stroke direction, transverse to the first direction, over a stroke length; and punching at least one hole in the profile by the punch unit; characterized in that, the stroke length of the punch is controlled by a control unit.

10. Method according to claim 9, wherein a displacement by the piston in the stroke direction is measured during punching a hole.

11. Method according to claim 9 or 10, wherein a pressure in the piston is measured during punching a hole.

12. Method according to any of the claims 9-11, wherein the method comprises the additional step of displacing an additional punch unit in the first direction.

13. Method according to claims 12, wherein the punch unit and the additional punch unit punch holes simultaneously.

14. Method according to any of the claims 9-13, wherein the punch unit punches at least two holes simultaneously, wherein the at least two holes have a fixed distance between them in the first direction and/or in a direction transverse to the first direction.

15. Use of a system according to any of the claims 1-8 or a method according to any of the claims 9-14 for punching holes in web and flanges of a U- profile for a truck or trailer chassis.